Twitter is a social networking and microblogging site whose users send and read text-based posts online. As of July 2014, the site had approximately 284 million daily active users, generating 58 million Tweets and 2.1 billion search engine queries daily.
Online radicalization to violence is the process by which an individual is introduced to an ideological message and belief system that encourages movement from mainstream beliefs toward extreme views, primarily through the use of online media, including social networks such as Facebook, Twitter, and YouTube. A result of radical interpretations of mainstream religious or political doctrines, these extreme views tend to justify, promote, incite, or support violence to achieve any number of social, religious, or political changes.
A document produced by the Department of Health and Human Services as part of their “Now Trending Challenge” to develop applications for monitoring disease outbreaks via Twitter. The document contains lists of various terms that are associated with a number of diseases from the common cold to diphtheria.