Online services that ask for the age of users as part of the registration process will be deemed to have "actual knowledge" of that information. Whether or not one’s site is directed to children, a registration process that includes an age field effectively turns the process into an "age filter," which must be operational to avoid the risk of violating COPPA.
Illustrating this point, Yelp, Inc. has settled allegations made by the FTC that it violated the Rule enforcing the Children’s Online Privacy Protection Act (COPPA), according to an FTC press release announced September 17, which also stated that Yelp agreed to pay a $450,000 civil penalty for the Rule violation. According to the complaint filed by the FTC in the U.S. District Court for the Northern District of California, the violation stems from a determination that Yelp had "actual knowledge" that children younger than 13 were accessing and registering with the Yelp website, and they provided personal information to Yelp, including full names and email addresses. Users who registered were also able to post reviews and other information on the website.