Facebook will be investigated by the European Union over a feature on its site that automatically identifies faces in users’ uploaded pictures, according to a report from Bloomberg.

The social network is under investigation from the EU’s Article 29 Data Protection Working Party and Ireland’s data protection authority.

The groups are looking into whether or not the feature violates privacy rules. Facebook didn’t immediately respond to a request for comment on the investigation.

The feature, which has been rolled out to test groups worldwide, is enabled by default, making the user’s responsibility to disable the automatic recognition.

Rep. Ed Markey (D-Mass.), who has addressed privacy and children’s privacy issues in the past, said in a statement that Facebook’s decision to make the feature “opt-out” was an issue.

“Requiring users to disable this feature after they’ve already been included by Facebook is no substitute for an opt-in process,” he said in a statement. “If this new feature is as useful as Facebook claims, it should be able to stand on its own, without an automatic sign-up that changes users’ privacy settings without their permission.”