content: Patents should require definite proof that you were the one to invent it first (or in the group that did it in which case the whole group gets to hold the patent). Anyone who comes by and shows definite proof he already was using that before can claim that patent and sue for damages (equal to the netto revenue of the patent minus the court cost). Any patent should be free to the public as soon as the holder (or each person from the group) dies.