Facebook is now blocking messages that contain links to torrent sites or other pirated content. Wired.com reports that Facebook has been blocking torrent links on Facebook walls and newsfeeds since last spring. If a user tries to send a message that contains a link to a torrent site, they receive a message stating, “This message contains blocked content that has previously been flagged as abusive or spammy.”

Facebook wrote in a written statement to Wired.com that, “We have systems in place to prevent abuse on Facebook and prevent spam which we’ll continue to deploy with the new Messages.”

Privacy advocates and watch dogs are questioning this move by Facebook, as known policing of the messages system could negatively impact the widespread adoption of this upgraded service. Also, the monitoring of email messages without proper notification could be a violation of federal wiretapping laws.

Wired.com further asked Facebook if the site searches messages for references to illegal drugs, underage drinking or shoplifting. Facebook declined to comment. This leaves room for speculation on what other searches might be actively screening user messages. Keep in mind, federal authorities recently made a trip to Silicon Valley in an attempt to obtain more access from Facebook and Google in their wire-tapping endeavors.

Facebook contends that their screenings and content blocking systems are designed to protect intellectual property rights. Will the property rights of some violate the privacy rights of others?