Adware firm 80solutions was sued this week, accused of deceptively distributing ad-serving software and preventing users from removing it, reports MediaPost. The complaint was filed in Illinois federal court by the Naperville, Illinois-based Collins Law Firm, which filed a similar class-action lawsuit against adware company Direct Revenue earlier this year. Sean Sundwall, director of corporate communications at 180solutions, said the company would defend itself.

The plaintiff in the 180solutions case is Illinois resident Logan Simios, who is asking the court to allow him to sue on behalf of some 20 million U.S. - and "hundreds of thousands" of Illinois - computer users who have had 180solutions software on their computers.

180solutions recently introduced software designed to ensure consumers' consent for installed adware; it also sued former distributors for installing the company's its software without obtaining consumers' permission. Since January, the company has ended relationships with 500 distributors, writes MediaPost.