Some 3,300 Android apps for children under the age of 13 may not be compatible with the US Children’s Online Privacy Protection Act (COPPA), research by the International Computer Science Institute found.

Researchers examined 5,855 Android apps from the US Play Store targeted at children and included in Google’s Designed for Families programme. They found “several concerning violations and trends” with roughly 57 per cent “potentially violating COPPA”.

For instance, 4.8 per cent shared location data or contact information without consent, 40 per cent shared personal information without applying reasonable security measures, 18 per cent shared persistent identifiers for prohibited purposes such as ad targeting, and 39 per cent showed “ignorance or disregard for contractual obligations aimed at protecting children’s privacy”.

The research revealed Google’s Designed for Families programme complies with COPPA, but “there appears to not be any (or only limited) enforcement” of its rules. Violations may be unintentional or due to misunderstandings of third-party SDKs, the group said as it urged Google to be more proactive about its vetting process for children’s apps.

The research did not explicitly determine if the apps violate US law, and the US Federal Trade Commission (FTC) may have to step in to decide.

Last week a coalition of US child advocacy groups asked the FTC to probe YouTube’s practice of generating “significant profits” from advertisements targeting children, and called for parent Google to be subjected to a fine “in the billions of dollars”.