Remember how the DEA got caught impersonating a woman on Facebook in an attempt to catch criminals who contacted her? Yeah, Facebook isn't at all pleased. It just sent a letter asking the anti-drug agency to promise that it won't create fake accounts or otherwise stomp all over the social network's terms of service. As the site argues, the DEA's moves "threaten the integrity" of its user base -- the point of Facebook's real identity policy is to foster trust, and sting operations violate that trust. Law enforcement isn't above this rule, the company says. It's not certain if the letter will have any effect; the Justice Department tells BuzzFeed News that it doesn't believe this trickery happens frequently. Whether or not that's true, it's safe to say that Mark Zuckerberg and crew have set some firm boundaries for future cases.

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