Facebook is challenging a gag order from a US court that is preventing the social networking giant from talking about three government search warrants.Facebook says the gags pose a threat to freedom of speech.

US investigators are demanding the personal communications and data of three Facebook users, but have told Facebook that the users can’t be informed of the probe.

Facebook, on the other hand, has stated that it intends to inform the unnamed trio and give them a chance to object to the warrants.

The investigation is believed to relate to charges against people who protested at President Donald Trump’s inauguration in January.