The Federal Trade Commission has ordered the popular video-chat app TikTok to pay $5.7 million after it allegedly collected personal information from children.

TikTok allows users to make short videos and share them. It's among the most popular apps in the world.

The Chinese company has agreed to settle allegations it violated the Children's Online Privacy Protection Act in the U.S. The act requires online companies to get parental permission before collecting data from children under age 13.

Children's privacy advocates applaud the decision but say parents must remain vigilant.

"It's very important for parents to really take a look at what their kids are looking at, the apps that they're using, and to make sure that the privacy settings are set to private, not to public," says Elaine Fagin, of Child Abuse Prevention Services.

TikTok says it's now checking ages and has created a new private environment for younger users.

"The new environment for younger users does not permit the sharing of personal information, and it puts extensive limitations on content and user interaction," the company said in a statement.

The FTC says this is the largest settlement obtained in a child's privacy case.