Windows 7 - Three Security Vendors to Help bit.ly Fight Spam.

The company operating bit.ly, the Internet's most popular URL shortening service, has enlisted the help of VeriSign, Websense and Sophos to protect its users from spam. Each of the vendors will provide bit.ly with fundamentally different URL checking technologies for what aims to be one of the most complete and reliable malicious URL protection solutions.
URL shortening is the practice of generating short aliases for long URLs. URL length might not count that much in the vast majority of cases on the Internet, but it makes a big difference for users of micro-blogging platforms where messages have a very restrictive character limit.