Microsoft has confirmed that users of its instant messaging app will not be able to send each other links to popular torrent site The Pirate Bay, citing malware fears.
"We block instant messages if they contain malicious or spam URLs based on intelligence algorithms, third-party sources, and/or user complaints. Pirate Bay URLs were flagged by one or more of these and were consequently blocked," Redmond told The Register in an emailed statement.
http://www.theregister.co.uk/2012/03/26/microsoft_censors_pirate_bay_im/It seems that this is a software based restriction not a network filter but I can't find anything definitively outlining how they've done this.
