How much information can be gathered? Look no further than the . By examining hours of video and social media posts made during the event, a taskforce was able to post pictures of over 100 suspected rioters online -- over 30 of which were identified by police.

But it's not just the big events that can be data mined. Even suspects who are quiet, and limit contact on social media only to known friends can be tracked.

"Cops will figure out who the associates of the suspect are," Altschuler explained. The police will then friend or connect to the associates, working to gain their trust, and then will eventually friend the target directly, or be able to glean information about the target through the associates.

In 2007, for example, a detective in Newark, NJ tracked the alleged killers of three college students by mining MySpace pages maintained by the suspects and their friends. In another, pictures and prose posted online by the killer of a 17-year-old Virginia college freshman connected suspect to the victim and revealed where her body was. (See: )

Investigators will also use social media platforms to actively locate a suspect. This is often done in narrow cases, Altschuler said, such as a focused and coordinated attack on child pornography rings. One strong characteristic of such criminals is that they are collectors, and almost always reach out to share with other collectors. If law enforcement officers can leverage a known suspect's knowledge, they can use that to identify other suspects. If they're lucky, Altschuler added, they can flip the suspect and gain knowledge about other criminal activity and persons through that person's own account.