Police are using social media to catch criminals in various ways: 1. Suspects are incriminating themselves by posting photos and messages on Facebook that show gang affiliation or admit to crimes. While suspects have an expectation of privacy, courts have ruled that information shared with friends on social media can be shared with police. 2. Undercover police accounts on social media pose as friends to gain information, which some see as deceptive but not illegal if the evidence is used in court. 3. Police obtain search warrants requiring social media sites like Facebook to turn over private messages and profiles as evidence, which has led to convictions for crimes like talking to underage girls. As law enforcement adapts to social media, people