I wonder, is it possible to create a license that would allow you to simply ban people who are being a dick about something from using it? Sure, it may turn away some people, since there's always a risk of abuse, but it's your work and as far as I know, you are the one who sets the terms.

If I'm not mistaken, most of the FOSS licenses (or maybe even laws?) guarantee you that you would be able to use the software even if the project later decides to change to proprietary license. But I assume you can simply specify in a licence "Everyone can use it, expect X.Y.Z".

Would that be legal? Sure, it would probably be pretty hard to enforce, but in some cases it could make for a pretty satisfactory (and petty, of course) C&D letters, for people that really deserve it. You insult the devs of a software your company depends on, demanding something while being a dick about it? Well, fuck you, no library for you and your company.