Criminals in the US are bragging about their murders, rapes and robberies on social networking websites, often with photos or video clips, which has made it easier for policemen to track them down.
Facebook, MySpace, Twitter and YouTube have become "everyday crime-fighting tools", the New York Post quoted police as saying.
Manhattan thief James Roberts gave policemen all they needed to bust him - bragging on his MySpace page a day after he mugged a man at a bus stop. Roberts, 27, sealed his fate with pictures of himself and his loot, which included an expensive watch and ring he swiped from the victim.
"He's sitting on the couch, and then there's a close-up of his hand with the ring out," a police official said.
Detectives showed the photo to the victim, who quickly identified the stolen ring.
Roberts and his accomplice, Darryl Calier, were convicted of robbery, and are serving five years each.
Prosecutors said Facebook revelations have been "instrumental" in busting up a ring of drug dealers who sold coke, ecstasy and designer dope at nightclubs.
"It's almost become unfair," said an official. "Facebook and MySpace are killing these guys."
The sites have been useful in breaking up gangs, solving sex assaults and tracking down stolen goods, police said. They also help find witnesses and missing people.
A heroin dealer, Tyrell "Handsome Rell" Blue, put up on his MySpace page a photo of himself with a wad of cash and a claim that he earned $250,000 a year.
That information was used against him when police charged him and five others with multiple counts of selling narcotics.
Lt. Kevin O'Connor, of the Manhattan North Gang Intelligence unit, is regarded as a social-media expert who trolls Twitter for clues about suspects.
"You can find a lot of gangs on MySpace. They actually have their own sites," said one investigator.