I'm sort of reading this thread and the Mastodon thread in disbelief at the defenders. Just change the names of the darn filters! (and not "iClarendon" and "iLudwig" for heaven's sake -- that is so childish.)
There are fights worth fighting out there -- abusive patent trolls, etc. -- this is not one of them. If this escalates they will lose 100% and waste tons of time and money, both of which could be better spent on actually building Pixelfed.
Sorry -- not the world's biggest Meta/FB/IG fan here but I am 100% with them on this one and if I were in charge I'd make the exact same threats. /rant over.