Websense has acquired startup Defensio for an undisclosed price, gaining tools to clean out the spam and malware that gets posted as comments to blogs, user forums and social-networking sites.

"More and more of our customers are deploying Web 2.0," says Websense CTO Dan Hubbard, adding there hasn't been much in the way of defensive measures to protect Web sites from the vast amount of spam and malicious content that gets posted on blogs and other sites that accept user-created content.

Malicious code posted as a fake YouTube video on the My.BarackObama.com site is one example among many, according to Websense.
Websense plans to add Defensio's technology to its own tools and services, such as ThreatSeeker.

Defensio CEO Carl Mercier started the company, which has only a couple of employees, a few years ago. Its Web-cleaning service -- offered free for personal use --depends on software developers incorporating Defensio's APIs into their Web sites.

About 10,000 blogs are said to have started using it. Websense expects to continue the Defensio model of use, even as it adds Defensio-based protections into Websense services. Pricing has not been established.