When a gang member was released from jail soon after his arrest for selling methamphetamine, friends and associates assumed he had cut a deal with authorities and become a police informant.
They sent a warning on Twitter that went like this: We have a snitch in our midst.
Unbeknownst to them, that tweet and the traffic it generated were being closely followed by investigators, who had been tracking the San Francisco Bay Area gang for months. Officials sat back and watched as others joined the conversation and left behind incriminating information.
Full story: Use of Twitter, Facebook Rising Among Gang Members via ABC News