Comment by bloak

A "defend or lose it" rule would have bad consequences, I suspect, except for certain types of lawyer who might benefit enormously.

I think it might be better if the recipient of such vague threats were able to themselves initiate a court case to clarify the matter. The party making vague threats might be ordered by the court to either produce their evidence within six months or give up their claim by granting a public licence or whatever.

But it's hard to see all the consequences of rules like that and there are plenty of lobbyists able and willing to provide bad advice to legislators.