[throwaway3646]

Correct, it's a user error, but in a corporate environment, this happens. Many scientists have their own recipes and you can't catch them all.

[matrss]

So with a fresh installation of one of those alternative conda clients and no user intervention it won't happen, right? On top of that you can block access on the network level as well.

Sure, when your employees are outside of the corporate network they can still download stuff from the default channels, but in the end it is no different than any other license violation they could do. At least with Anaconda there is a semi-effective fix.