Message Labs – part of internet security guru Symantec – is warning that shortened URLs are becoming an issue in terms of spam.

This graph shows how the inclusion of shortened URLs in spam email has increased from practically nothing a to almost 2% in just a few days:

Shortened URLs are perfect for spammers because not only do they mask dodgy sounding domain names that users would usually be wary of, they also help spam mail bypass anti-spam programmes. Services such as tinyurl are also free and require no registration.

Matt Sergeant from Message Labs, said: “The entire trust model of clicking on the URL is completely broken,” he said. He also said it was impossible to trust URLs on Twitter as many people retweet links, often without even clicking on them first themselves.

(via NYTimes)