[heimidal]

"Squatting" a trademark generally isn't possible; if you can't prove use of the mark, the USPTO will simply cancel your registration. I imagine their activity related to the mark would be covered in any potential court proceedings and would be Facebook's primary defense.

[munk-a]

Yea - but having a github repository with active development and a meta-logo dating back to early 2021 would probably be pretty compelling to prove active use. This is definitely going to be a headache for somebody but I can't imagine the story as this letter tells it (FB reaching out repeatedly to acquire the name and then going ahead regardless) is a perfect telling of events. Either FB was totally unaware of this company's existence before today or else their lawyers looked over the company and didn't think it was a threat to their usage.