When they pull people over for that, they're supposed not to f ex follow a car around secretly in order to increase the number of violations they can book them for. Also traffic violations usually only leads to the car and your person being searched at most, not your house, computers and Internet history. It's also never retroactive yet like it could be if they decide to check the cars computer system to determine you were ever in the vicinity of a crime, in an unreported accident, went the wrong way on a freeway, drove off-road illegally, didn't follow the speed limit or failed to stop at stop signs. They don't need actual retroactive laws to be able to target people for persecution when they've made everyone a lawbreaker and they get to decide how thorough they investigate the suspects past and how much of that they'll prosecute him for. With all those options in place, they could simply rely on pure chance to get people they don't like to be caught for one crime if they're only disliked for being part of a large group. If they're very important, they're likely famous or under surveillance anyway, which makes it much easier to find one crime they need to book them for dozens or thousands if IP laws are considered as well.