The European Commission is probing two platforms and two app stores about their compliance with EU digital regulations designed to protect minors.

The Commission has sent requests for information to Snapchat, YouTube, Apple Store and Google Play on how they protect kids on their platforms under the Digital Services Act, the Commission’s Executive Vice President Henna Virkkunen said in Denmark Friday.

All four are designated as Very Large Online Platforms under the regulation because they have more than 45 million users in the European Union, so they have to follow strict risk assessment and mitigation provisions.

The Commission is asking the businesses to provide information on their age verification systems, as well as on how they prevent minors from accessing illegal products, including drugs and vapes, or harmful material, such as content promoting eating disorders.

“Today, alongside national authorities in the member states, we are assessing whether the measures taken so far by the platforms are indeed protecting children,” EU tech chief HennaVirkkunen said.

The DSA is an EU landmark law that requires online companies to do more to tackle illegal and harmful content on their platforms.