AVG has become the first antivirus vendor to offer a privacy filter to monitor and block websites and ad networks that silently collect Internet usage data from consumers, the company has announced.

Available from today in a service pack for all paid and free AVG antivirus users, DoNotTrack is a plug-in for Internet Explorer, Mozilla and Chrome that keeps tabs on which sites are collecting data as users browse the web.

Some of this will be fairly innocent web analytics of the sort gathered by every site to monitor how visitors interact with sites, but AVG said users should also be more aware of social media applications that collected extensive data usage information and ad networks. Both of these could be intrusive in search of the information necessary to serve context-aware advertising, AVG said.

AVG users will be able to block or allow these on a case-by-case basis, controlling what data is tracked depending on their assessment of a particular site.

“When you visit a site a lot of data is being collected about you,” said AVG CTO, al Ben-Itzhak. “Our goal is to make you aware of what is being collected.”

The company had designed DoNotTrack as an ‘active’ tracking system after noticing that the passive voluntary approach pioneered by World Wide Web Consortium (W3C) was often being ignored by providers, he said.

A good example of this is Mozilla's Boot to Gecko operating system for smartphones, which will include support for this approach. Longer run, Ben-Itzhak thought standardised efforts were the best approach to the privacy issue but would take time to mature.

DoNotTrack based its assessment of websites and networks on their stated privacy policies.

The latest Service Pack also includes a new WiFi Guard feature which monitors and controls access to new access points as a way of blocking rogue SSIDs.

DoNotTrack is available to all paid users of AVG’s antivirus client but also AVG Anti-Virus Free.