No, that's not entirely true either. Depending on where the proprietary bits are, it's the other side that is the problem. It is a violation of the GPL. So the

No, that's not entirely true either. Depending on where the proprietary bits are, it's the other side that is the problem. It is a violation of the GPL. So the usual workaround is to shift the responsibility to the user so that incompliant stuff is done by the user by the way of a script that runs on the user's behalf.