In a five-page memo sent out to officers last week, the NYPD presented official guidelines regarding the use of social media within probes.

The Daily News reports Police Commissioner Ray Kelly said officers working on investigations involving social media are permitted to register aliases under the department and use "department-issued laptop whose Internet-access card can’t be traced back to the NYPD."

In 2011, the NYPD formed a social media unit to crack down on suspects publicizing their crimes via their Facebook and Twitter accounts.

While police have been successful using social media to bust criminal activity, Christopher Dunn of the New York Civil Liberties Union says officers must be mindful of privacy.

Dunn said, "Electronic undercover work is fine. But we worry about the ease with the police can use deceit on the Internet to monitor private communications. Police infiltration of social media should be closely regulated."

While they're at it, the department may want to issue guidelines on their own social media conduct. 17 NYPD officers were disciplined last month for operating a Facebook group filled with racist and violent comments targeting participants in the annual West Indian Day Parade.

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