@Suiseiseki
@colinsmatt11

> The odd one out it the BSD-4 clause, which can possibly become nonfree just with standard free software development practices, as complying with the license becomes difficult or impossible if there's more than one copyright holder

It is not difficult nor impossible, rather very inconvenient if you're a commercial organization, the whole point of it is that FAGMAN will stay away from that software if they're looking for something to make malware of. You can also offer special licensing to organizations that you deem trust worthy or that will treat the general public with respect (for example Trisquel or Hyperbola projects) if they get in contact with you, by offering them a GPLed copy of that project.