By routing all links submitted to Twitter through this new service, we can
detect, intercept, and prevent the spread of bad links across all of Twitter.
Even if a bad link is already sent out in an email notification and somebody
clicks on it, we’ll be able keep that user safe.

Initially the service would be rolled out on direct messages he said, since
these were the most likely to be used for phishing and other scams. Such
messages are usually sent out when a Twitter account becomes compromised by
malware distributors.

A URL scanning service for social media sites was
widely
discussed at this years
RSA
2010 conference, which was held last week. Security professionals are
becoming concerned at the
increasing
volume
of malware attacks using social media, which seek to capitalise on the trusted
nature of such communications.

Source: www.v3.co.uk