The owners of AdultFriendFinder.com were accused of pushing the ads through spyware that was often installed without consumers’ knowledge, the FTC said in a complaint set to be filed Thursday in federal court.

Victims who had never even visited sexually explicit sites would suddenly find themselves face to face with full-screen pornographic ads after typing innocuous sounding terms such as “flowers,” “travel,” and “vacations” into search engines.

According to the FTC, AdultFriendFinder.com, which touts itself as “The World’s Largest Sex & Swingers Personal Community,” and its affiliates use pop-up ads to drive traffic to its Web sites. Some of the ads have included graphic depictions of sexual behavior, exposing consumers, including children, to sexually explicit images.

Such ads were displayed to consumers who were searching online using terms such as “flowers,” “travel,” and “vacations.” In some cases, defendant’s sexually explicit ads were distributed using spyware and adware.