So, FIFA has just confirmed they have received a complaint from Atlético, due to Barça tapping up Greaseman.
This happens just a few days after Barça's director of club relations was stupid enough to say on camera that they were having talks "with different players, perhaps including Griezmann, as we usually do"

If this proves to be more than a nothingburger, Barça could be banned from making transfers again. Roma was banned for a year for tapping up Mexes some time ago. For now, Barça has denied contacts with the player in an official statement.