Federal Judge James Holderman certified a class of “all individuals who have had, at any time since 2005, downloaded and installed comScore’s tracking software onto their computers via one of comScore’s third party bundling partners”. Holderman also certified an additional subclass of “all class members not presented with a functional hyperlink to an end-user licence agreement before installing comScore’s software onto their computers”.

Estimates put the size of the class at up to a million people.

The class certification applies to claims brought under the Stored Communications Act, the Electronic Communications Privacy Act and the Computer Fraud and Abuse Act.

Holderman denied class certification for the plaintiff’s unjust enrichment claims.

Mike Harris and Jeff Dunstan first sued comScore in 2011. They allege that the company exceeded the scope of a consumer’s consent to monitoring by intercepting phone numbers, social security numbers, usernames, passwords and credit card numbers, among other personal information.

ComScore has said that the claims in the lawsuit are “without merit”.