Really? How they will know if particular bitcoin address or entity uses Coinjoin? I think coinjoin is about privacy on top of Bitcoin. And if it is illegal, how they will able to sue some person/entity using coinjoin? Since as far as I know once you use coinjoin, it will really help you not to identify the original input, just what @figmentofmyass said.
I' m a bit confused about this, because once they will know a particular address if uses a coinjoin, then coinjoin purpose is no more, coinjoin has no help on privacy anymore.
There's a few blockchain explorers that lets you know if a transaction is possibly coinjoin. I've looked up the video that zhzz mentioned and to be specific he mentioned europe, i'm guessing it's because of the bestmixer incident.
some exchanges have terms (or at least suspected policies) against mixers. but i've never seen any terms specifically against coinjoins, and i've never heard of anyone getting their account closed over it.
This
user got his account locked temporarily because some of his transactions were done with coinjoin.