The New York Police Department is fine with cops assuming fake names to patrol Facebook and Twitter, but the public feels differently.

Police Commissioner Raymond Kelly just issued a memo that allows officers involved in probes to register aliases online, according to the New York Daily News . The restriction is that police must only use those aliases while using department-issued laptops with wireless access cards that can’t be tracked back to the NYPD.

There’s no doubt that keeping tabs on social media makes it easier for cops everywhere to fight crime. On Thursday, police were able to successfully track down a sex offender through his girlfriend’s Facebook page. But some think allowing officers to obscure their identities as students, coworkers, or even kids is taking social media stalking too far.

Christopher Dunn, associate legal director for the New York Civil Liberties Union, told the New York Daily News that he thought the privilege could be too easily abused.

“Electronic undercover work is fine,” Dunn said. “But we worry about the ease with the police can use deceit on the Internet to monitor private communications.”

Facebook has signed off on the policy. A spokesperson told the New York Daily News that as long as users, including cops, registered initially under their real names, they were fine to use pseudonyms after that. That means that while Facebook knows exactly who your real friends are, you may not.

UPDATE: In an email to the Daily Dot, a Facebook spokesperson clarified that Facebook's policy of allowing pseudonyms does not extend to false aliases. For example, Lady Gaga can use her stage name on Facebook, providing she registers under her real name, but "pseudonyms aren’t used in the case of a user named, say, 'John Smith' wanting to be 'George Smith.'"

Photo by Paul Stein/Flickr