I understand the incentive, but if there is an obvious violation and you ignore it for years, without even a letter to the violator, you should probably not be

I understand the incentive, but if there is an obvious violation and you ignore it for years, without even a letter to the violator, you should probably not be allowed to decide to enforce it after that tech has become entrenched. It should be on the patent holder to explain why they didn't complain when the problem was small. Trademark owners can lose if they don't stand up early with a crew and desist.