Children’s advocacy groups including Fairplay and Common Sense Media are asking the Federal Trade Commission to investigate Google, saying the tech giant serves personalized ads to kids on YouTube despite federal law prohibiting the practice.

The letter follows a report from The New York Times last week that found that ads on YouTube may have led to the online tracking of children. The federal Children’s Online Privacy Protection Act, or COPPA, requires kid-oriented websites to get parents’ consent before collecting personal information of children under 13.

In response to the Times report, Google said last week that it did not run personalized ads on children’s videos and that its ad practices fully complied with COPPA. When ads appear on children’s videos, the company told the Times, they are based on content, not user profiles.

Google’s parent company, Alphabet, agreed in 2019 to pay $170 million to settle allegations that YouTube collected personal data on children without parents’ consent.

U.S. regulators on Wednesday announced a settlement with the company that runs Dollar Tree and Family Dollar aimed at improving worker safety at thousands of the bargain stores across the country.

Labor Department officials cited hazards at the stores including blocked exits, unsafe storage of materials, and improper access to fire extinguishers and electrical panels.

Under the agreement, the chains operated by Dollar Tree Inc. are required to find the “root causes” of violations that the Occupational Safety and Health Administration has repeatedly cited at multiple stores and fix them within two years, the department said.