Germany’s state telecommunications agency has banned smartphone watches designed for kids, saying that the “the devices violated Germany’s strict surveillance laws,” according to The Guardian. The agency also encouraged parents to destroy the watches.

“Via an app, parents can use such watches to secretly listen to a child’s environment. They are to be seen as a prohibited transmitter,” Jochen Homann, president of the Federal Network Agency, said in a statement, according to The Guardian. “Our investigation has also shown that parents have used the watches to listen to teachers in the classroom.”

Gizmodo reports that the ban comes nearly a month after the European Consumer Organization (BEUC) issued a statement saying that these types of watches are a threat to kids’ privacy, though the Federal Network Agency didn’t reference the BEUC’s findings in it’s own statement. In addition to urging parents to destroy the devices, the Agency has also asked Germany’s schools to watch out for their usage in the classroom.

Read more about the ban on The Guardian.