CHICAGO (AP) — New law enforcement materials compiled by the Chicago Crime Commission say the embrace of social media by gangs to taunt rivals or conceal drug-dealing operations is the biggest change in how gangs operate compared with 10 years ago.

The materials provided in advance exclusively to The Associated Press before its release Tuesday in a Gang Book describe how Facebook, Twitter and other sites have radically altered gang culture in Chicago. They’ve had similar influence on gangs nationwide.

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Gang-conflict mediator Rodney Phillips says there’s nearly always a link now between gang violence and something posted online. Social media broadcasts gang taunts and insults to thousands in an instant and there’s immediate pressure to retaliate.

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Gang Books are used as a gang guides for regional police. That last was published in 2012.

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