I think that the good approach was taken by Twisted Matrix:

https://twistedmatrix.com/trac/wiki/CommunityCode

"official" Twisted projects retain the "Twisted" name. Community projects related to twisted use the "tx" prefix. This allows both a clear identification of related code, and present no issue with trademarks.

Alright, so there isn't a problem at all. Docker isn't forcing anybody to not use the name 'docker' nor did they sue anybody.

Nothing to see here, move along..

Docker is great, but "@dockersucks" is protected speech.. Docker can't prevent its use.

But they can ask people to stop, and they can reply that they don't "allow" it when asked about it. Which is what they're doing.

This was a very obvious and straight-forward answer to the question he asked, and he calls them assholes for it and claims they don't care about the community.

They can protect their trademark without shitting on the community, and they're doing just that. This is really just a rant from a guy who got an answer opposite to the one he wanted, yet obviously expected this answer or he wouldn't have asked in the first place.

If they say "we don't allow it" in regards to protected speech, it's roughly the same as peeing into the wind. lol I agree with you about everything else, there was no real need to call them out for this one.