New York Attorney General Eliot Spitzer has filed a suit against Direct Revenue, alleging the company secretly installed millions of pop-up advertisements on consumers' personal computers, writes ClickZ (via MediaBuyerPlanner). The lawsuit seeks to stop the firm from installing spyware or sending ads through pre-existing applications.

"Surreptitiously installed spyware and adware harm consumers and businesses, and my office will continue to prosecute these practices aggressively," said Spitzer. The AG's office said the company's adware was bundled in free software, but consumers were unaware of the download.

Direct Revenue's legal council said the company is "mystified" by the lawsuit and that it used practices that it "believed at the time and believe today were appropriate and legal."

The company has posted a rebuttal to the attorney general's charges, in which a company spokesperson is quoted as saying, "Mislabeling our products as 'spyware' does a disservice not only to our company, but also to the public by creating an atmosphere of hysteria, confusion and inaccuracy."