(AP) - A coalition of child advocates and consumer groups is asking the Federal Trade Commission to investigate Google's YouTube service for improperly collecting kids' data and targeting ads to them.

YouTube has become widely popular among children despite its terms of service that block users under age 13. A formal complaint being filed Monday says Google's practices violate a federal child privacy law.

Child advocates and consumer groups are asking the Federal Trade Commission to investigate and impose potentially billions of dollars of penalties on Google.

YouTube's business model relies on tracking IP addresses, search history, device identifiers, location and other personal data about its users so that it can gauge their interests and tailor advertising to them. But that model isn't supposed to work for U.S. children, who are protected by the Children's Online Privacy Protection Act. That's a 20-year-old law that prohibits internet companies from knowingly collecting personal data from kids under 13 without their parents' consent.

The coalition accuses YouTube of violating COPPA and deliberately profiting off luring children into what Chester calls an "ad-filled digital playground" where commercials for toys, theme parks or sneakers can surface alongside kid-oriented videos.

YouTube said in an emailed statement that it "will read the complaint thoroughly and evaluate if there are things we can do to improve. Because YouTube is not for children, we've invested significantly in the creation of the YouTube Kids app to offer an alternative specifically designed for children."

Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.