Google and the Digital Advertising Alliance have thrown their weight behind the drive to bring a Do Not Track feature to popular browsers, in a bid to improve users’ privacy.

As the Wall Street Journal reports, major advertising companies and others who use tracking data have agreed to honour the system which is already implemented in Firefox, Internet Explorer and Safari. This means that when activated, the feature will restrict the data websites can collect about users through cookies.

Ad personalisation will be blocked, and companies agreeing to the plan have pledged not to use the browsing data for employment, credit, healthcare or insurance purposes. However, cookies will still be able to be used for market research, product development and law enforcement. The WSJ adds that Facebook’s Like buttons and similar features that rely on cookies for recognising logged-in users off-site will still work.

Google’s Chrome browser is set to add Do Not Track support by the end of the year, while the Digital Advertising Alliance, a consortium which represents more than 400 companies, is working to honour the standard within nine months.

The White House supports Do Not Track as it calls on Congress to pass a ‘privacy bill of rights’ (more details in this Cnet report), however the concept has faced criticism from those who fear that advertising-supported websites won’t be able to continue to offer free access to their content without the higher revenues that personalised ads generate. Supporters of Do Not Track argue, though, that personalised advertising accounts for such a small percentage of the overall online ad market that the effect would be negligible.