The website that Hannah Smith, 14, was using shortly before she died is called Ask.fm.
Launched in 2010, the social networking site invites users to pose questions which other users can respond to - often anonymously or with pictures and videos.
Joining the website takes only a few clicks and users only have to provide a name, email address and date of birth.
According to the technology website CNET, the site has some 60 million users of which half are under the age of 18 and a portion under the age of 13.
It reports that teenagers see the platform as "fun and dangerous" because of the option of staying anonymous and the common use of profanities.