A web search dataset released by the AOL is publicly accessible for data analysis (see similar research in [26]). This dataset is currently the largest publicly accessible search query log on the Internet and represented approximately 1.5% of the total number of search queries conducted through the AOL search engine, which had a 6.7% share of the overall search market in 2006 [27]. The dataset was a random sampling from all AOL subscribers’ search queries between March and May 2006 and consisted of roughly 21 million instances of such queries, collected from roughly 657,000 AOL subscribers [28].

Each entry contained an anonymous service subscriber identity code (ID), time of submission, the rank position, and domain of the clicked-through webpage. A single search query represents one individual click on the “search” button as initiated by a user, regardless of whether the user clicked on any of the webpages in the results page(s). A unique set of one or more keywords used in a search query constitutes the search term(s). A click-through is where a webpage in the returned search results was accessed by an individual click following a single instance of a search query and consequently that webpage is referred to as a clicked-through webpage. The number of click-throughs can also be referred to as traffic.

In response to concerns about privacy, additional measures were taken to replace all possible personal identifiable information from the dataset before undertaking analysis. Each unique subscriber was assigned a random identifier number. The Human Research Ethics Committee for Nonclinical Faculties of the University of Hong Kong approved the ethical aspect of the study protocol.

To address our first research question, any search query containing the keyword suicide in the search term(s) was retrieved from the dataset, and the contents of all clicked-through webpages following these search queries were then content analyzed to derive categories for analysis. Researchers PW and RY independently categorized all of the identified webpages, and each created an initial coding frame. The two coding frames were then compared and refined to develop a consensus coding frame. All of the clicked-through webpages were subsequently individually re-categorized by researchers PW and RY to form the final coding frame. Using the final coding frame, coding disagreements between PW and RY that could not be resolved were referred to the third researcher KWF, who analyzed those blinded to the codes assigned by researchers PW and RY. In most cases, this approach resolved the disagreements but when a decision still could not be made, researchers PW, RY, and KWF jointly visited the clicked-through webpage and discussed the rationale for their coding until agreement was reached.

To address our second research question, web domains from the webpages in the above 11 categories that appeared to encourage suicide or promote the individual right of dying by suicide regardless of medical grounds [23] were identified and content analyzed, and all the search terms used to access these pro-suicide web domains, including ones that did not contain the keyword suicide and additionally the ones found through the first stage of data coding, were identified and examined.

We found 5526 search queries (0.026%, 5526/21,000,000) that included the keyword suicide. The 5526 search queries were generated by 1586 unique search terms and 1625 unique users (0.25%, 1625/657,000). The three most frequently used search terms were “suicide” (9.79%, 541/5526), “suicide girls” (5.34%, 295/5526), and “how to commit suicide” (2.17%, 120/5526). Of the 5526 search queries, 3392 (61.38% of 5526) clicked through to a resulting webpage.

Of 3392 search queries with a click-through, 1344 unique webpages were clicked through by 930 unique users using 908 unique search terms. Of the 1344 webpages, 30 webpages were found to be inaccessible during the study period (October to November 2011) and returned error messages such as “page could not be found”, “forbidden access”, or “unable to display page” resulting in 1314 accessible clicked-through webpages. The three most frequently used search terms were also “suicide” (7.61%, 257/3392), “suicide girls” (4.95%, 168/3392), and “how to commit suicide” (2.74%, 93/3392).

Each clicked-through webpage was classified into 11 categories:

Among the 1314 webpages, the proportions of the webpage categories are as follows: entertainment (writings, pictures, music about suicide) (30.14%, 396/1314), scientific information (18.26%, 240/1314), community resources (14.54%, 191/1314), specific case/incident (11.04%, 145/1314), specific means (10.65%, 140/1314), overdose and suicide (4.72%, 62/1314), religion and suicide (4.11%, 54/1314), physician-assisted suicide (2.51%, 33/1314), discussion forum (2.28%, 30/1314), families and friends of suicide/attempt (1.60%, 21/1314), and afterlife (0.91%, 12/1314).

From the search queries, 78.01% of the traffic (2646/3392) went to a webpage link belonging to first page of the search results, 9.17% (311/3392) of the traffic went to the second page of search results, and 10.23% (347/3392) went to the third to fifth page of search results, while only 2.59% (88/3392) trickled to the sixth page or onwards in the search results. These results are generally consistent with current search engine data where links that are higher in the search engine results page, especially on the first page of the search results, tend to get majority of the traffic [29,30].

Table 1 shows the three most commonly used search terms for each webpage category, their usage frequencies, and the number of unique users for each search term. For webpages in the entertainment category, for example, the most commonly used search term that resulted in a click-through to a webpage was “suicide girls”, which was used 247 times (number of queries = 247) by 23 unique users.

When suicide was used as a single keyword search term (number of search queries = 256; 19.48%; 256/1314), users mostly clicked through to webpages that belong to the “community resources” (130 search queries), “scientific information” (69 search queries), and “specific means” categories (24 search queries). In contrast, when the search term “how to commit suicide” was used, the users most commonly clicked through to webpages in the “specific means” (70 queries), “overdose and suicide” (17 queries), and “religion and suicide” categories (13 queries).

The search terms most commonly used to access webpages in the “entertainment” category included the keywords in the names of a specific adult website and a novel cum movie. The “specific case/incident” category top search terms involved the keywords in the names of two famous individuals and a teenager who died from suicide; of note, each of these three search queries were contributed by one single user. Webpages in the “specific means” category were most commonly clicked through when users used the search terms “how to commit suicide”, “ways to commit suicide”, and “suicide”.

Table 2 shows the top three most clicked webpages of each category. The webpages with more than 40 click-throughs during the data collection period included “http://www.suicidegirls.com” (entertainment), “http://suicidegirls.com” (entertainment), “http://metanoia.org” (community resource), “http://www.satanservice.org” (specific means), and “http://www.cdc.gov” (scientific information). In the entertainment category, the two most clicked webpages led to the same web domain, which was an adult website. Wikipedia, an online information resource (Figure 1), followed by an automobile parts branded e-store (“http://www.suicidedoors.com”) were also in the most clicked webpages for the entertainment category. For the specific case/incident category, Wikipedia came up on top again with the most click-throughs, in addition to a news webpage and a social networking webpage.

Among the 1314 accessed webpages, we could identify only two clicked-through websites that were considered pro-suicide. They are “http://www.suicidemethods.net” and “http://www.churchofeuthanasia.org”. The two websites not only provide information on methods of suicide but also portray a positive attitude towards the choice of using suicide as a way to ease pain. Table 3 shows the searches terms that were used to access the two websites (ie, “how to kill yourself”, “best way to commit suicide”, and “euthanasia”), the frequency of their usage, and the number of unique users for each search term. We found that the commonly used search terms included “pictures of murder by strangulation” and “photo of a severe burn” for “http://www.suicidemethods.net” and “committing suicide with a gas oven”, and “hairless goat” for “http://www.churchofeuthanasia.org”. It is noteworthy that 23 and 14 unique users visited “http://www.suicidemethods.net” and “http://www.churchofeuthanasia.org” respectively during the data collection period. It is important to view these numbers in context, especially given the fact that a single unique user contributed to the entire search query frequency of both “committing suicide with a gas oven” and “methods to commit suicide”, while the top two of search query frequency for “http://www.suicidemethods.net” were a result of only two unique users.

In traditional media, newspapers, radio, and television were the major sources for information and their consumers were perceived as passive receivers of information. Information portrayed in traditional media was mainly contributed by professional journalists, and hence, regulation of that information was relatively straightforward. In terms of suicide information in traditional media, since information about suicide cases are presented and received passively by the masses, media reporting guidelines on suicide information developed for professionals has been considered as a core prevention strategy [31]. With the development of the Internet, we have stepped into the information age, which has revolutionized the ways we consume and produce information and transformed how we organize knowledge [32].

In the Web 2.0 era, the new media is interactive. People become proactive consumers and producers of information. Not only can people search for information and contribute, messages and information can also be widely and easily shared among friends via social media and networks. The ease and low cost of creating and copying content on the Internet contributed to its exponential growth and now, the amount of information that can be found on the Internet can be considered as almost infinite. In 2004, Google’s whole data storage was approximately five petabytes, which is the quantity of data a thousand times larger than the Library of Congress’s print collection [33]. According to a recent survey, there are 346,004,403 websites on the Internet as of June 2011 [34], and Google announced on July 2008 that it had processed over one trillion unique URLs [35], while Bing estimated that there were one trillion pages of content in 2009 [36]. Internet users, who can now also be contributors of information, do not have any obligations to follow reporting guidelines. Furthermore, content on the Internet can be easily copied, re-posted, cached, and reproduced in mirror-websites, and blocked websites can be bypassed easily through encrypted connections. A good example is the WikiLeaks site “http://en.wikipedia.org/wiki/WikiLeaks”, which had many mirror websites created when authorities tried to shut down and remove all the content from original website. The properties of this new medium make restricting access to particular websites difficult and impractical. Although the exact number of pro-suicide websites on the Internet is unknown, it is close to impossible to remove such websites from the Internet, regardless of whether they are easy or difficult to access.

Internet users use the Internet for various reasons. Segev and Ahituv conducted a cross-national analysis of popular search queries used in Google and Yahoo! over a 24-month period from January 2004 to December 2005 and found that there are cultural differences related to Internet usage [10]. They found that in many English-speaking and Western countries, the most popular searches were related to entertainment. According to the Pew Internet and American Life Project, information searches and email are the two major online activities among adult Internet users [37], and communication and entertainment are the most common ones among young people [38]. Accordingly, the “uses and gratifications theory” [39], a well-known theory in the field of media studies, states that the information people choose to access is largely dependent on their media consumption needs and desire. In other words, although negative information is easily accessible through new media, whether people access it largely depends on what they are looking for.

Our findings have provided a glimpse into the information consumption preferences of online users and corroborates prior studies on people’s Internet usage. Even for a domain-specific topic, suicide, our study generated consistent findings that most search engine users in the United States used suicide-related queries to search for websites that belong to the entertainment category.

Although pro-suicide websites and websites that contain detailed information on suicide methods can be accessed easily, the majority of search engine users, at least in the United States, did not access them using suicide-related queries. A number of keywords used to access pro-suicide webpages were instead related to violent or bloody pictures including “gory pictures”, “gory photos”, and “homicide pictures”. With these queries, we suspect that those who accessed the websites might not have an intent to die. Westerlund [40] has suggested that the fascination with pro-suicide content, particularly the morbid and violent descriptions may be a manifestation of a meaningful process in which the producer or consumer of this content is building an identity, acting out aggressive impulses, or even rebelling against the dominant culture. An interesting future study would be to explore the motivations behind why non-suicidal individuals access suicide-related information. The AOL data are very much based on a Western population and according to Segev and Ahituv’s findings [10], we do not know whether people in other countries behave similarly or differently. Recently developed free tools, like Google Trends and Google Insights for Search, may help to conduct a cross-national comparison study on this topic. With that information, however, we are still far from understanding how Internet users process information collected from the Internet and whether pro-suicide information leads to suicidal behaviors.

In-depth interviews with individuals with nearly lethal suicidal behavior may help to understand this phenomenon. In Biddle et al’s study [25], 22 individuals who survived nearly fatal suicide attempts were interviewed on the information sources that informed their choice of suicide method. They found that about 36% of the attempters’ choices of suicide method were found through the Internet. Interestingly, according to the transcripts cited in their paper, some attempters were “inspired” by online footage of Saddam Hussein’s execution or Wikipedia, which contains detailed information on suicide methods despite being a general information website. They wrote “the sites accessed by these respondents tended to be those containing professional information and resources (including online chemists), general knowledge sites (eg, Wikipedia), or news sites, including BBC news. Specific ‘suicide sites’ were accessed less frequently…” (p.705 of [25]). This information is essential to inform further development of suicide prevention work on the Internet.

In our study, we found that a small group of individuals intentionally searched for information about ways to complete suicide and an even smaller group of individuals were eager to find discussion forums using suicide-related keywords. A few individuals used queries like “suicide by overdose of XX” or “suicide by XX” to get access to webpages that provide information on prescribed drugs and suicide. In contrast, websites that include information on suicide means were accessed by larger numbers of unique users. One individual used a specific discussion forum address as a query (“xxsuicide’s xanga site” as shown in the table) to get access to that particular webpage 10 times.

There is a lack of research on suicide pacts arranged online, and so it is difficult to predict the major consequence of a large number of discussants getting access to this sort of discussion forum. On one hand, there have been some documented instances of completed suicide pacts in Japan [18], and on the other hand, there is evidence for the positive effects of joining an online community, like Facebook, which may enhance ones’ positive affective state and also increase ones’ social support [41].

Current efforts to reduce the potential negative impact of the Internet on suicide include remedial actions like removing and blocking entries of harmful websites by using Internet filters, constant monitoring of potential harmful websites by “web-based police officers” as implemented in Japan and Korea, and displaying helpline resources information while users key in suicide-related queries. These strategies are in place in an attempt to either shield suicidal and vulnerable individuals from suggestive material or abort their suicidal wishes by diverting their attention to help resources. There are several challenges that these strategies face. First, these strategies do not observe the way that information is created, found, and accessed online. Accordingly then, restricting or removing potentially harmful websites is an arduous if not impossible task. Furthermore, cyber regulations are extremely difficult to enforce since the Internet is not clearly under any jurisdiction, and identification of a physical user can be elusive.

Instead, it is important to further investigate the natural online behavior especially of vulnerable individuals and integrate that information with the way that search engines provide information. With the Internet inundated with information, the major search engines, ie, Google, Bing, and Yahoo!, have complex algorithms to return relevant search results to users. Consistent with the uses and gratification theory, relevance in a search engine is defined by variables such as user popularity, credible web domains, and high-quality content. As such, well-made and informative websites will tend to rank higher in search results and also be visited more often. Consequently, instead of the labor-intensive strategy of finding, sorting, and removing potentially harmful websites, more resources and effort should be spent on developing high-quality, informative, interactive, and user-friendly websites that maximize the likelihood of ranking highly in search results and therefore, being found and accessed.

Also, more recent studies find that the Internet provides more positive than negative effects on the vulnerable, especially in enhancing the social support of isolated individuals though social networking sites [11,42]. Mental health providers and researchers should make use of Information and Communication Technology (ICT) in strengthening their traditional practices in a fashion that could not be achieved in pre-digital times.

Our research presented the naturalistic search behavior of search engine subscribers using any search terms with the keyword “suicide”. Currently we know that cybersuicide or Internet suicide pacts represent a small fraction of overall suicides. While those attempting suicide have searched for suicide-related information on the Internet before completing the act, we also know that the Internet can provide a unique platform to reach those individuals previously inaccessible, and web-based psychotherapies are producing promising results in helping depressed individuals, with the acknowledgment of the potential digital divide phenomenon. As such, it can be concluded that we should neither underestimate nor overestimate the potential negative impact of the Internet on suicide.

However, the threshold between offline and online activities is quickly receding and in the near future will soon disappear. It is uncertain how much of today’s searching, and even learning, behavior will remain unchanged. There are plenty of daily examples that show how much of our learning behavior has transformed. “Siri” (Speech Interpretation and Recognition Interface) is an intelligent personal assistant and knowledge navigator that functions as an application for Apple’s operating system and answers questions, makes recommendations, and performs actions by delegating requests to a set of web services to iPhone users. Google Images, a searching tool for images on the Internet, may help Google users to search for visual information using image or pictures. These are just a few examples. Suicide research and prevention strategies must keep up with the emerging trend and pace of ICT in order to prevent more unnecessary tragic deaths.