As to this problem & remedies ... Sad to say, they are those who wish to take the easy way out. There used to be a law that it was illegal to steal edible meat. I was told this in the 70s or 80s. I recall one game warden back on my days in the 80s on the Trinity River (a few miles below TX 21 bridge). Very friendly one who was a champion of all legal fishermen. It had just been made a law as to tagging one side of your trotline. He explained why it was best to tag both sides & gave an example of one he was checking (for legality). It was hung & he could not get the other side. The side he was on, did not have the tag. He could not get the other side to look. So by law, he was required to pull it, as no tag, it was not legal. But as he was retrieving it, it came loose & then he could retrieve the rest that he could not find or get to. Sure enough, it had the legal tag. So he neatly piled it on the bank on that side for the fisherman to hopefully find. He explained that he would not have pulled it, had a tag been on both sides.
He also said it was not required to tag throwlines. But he explained that if it was tagged & he came upon someone running it, that did not match the tage, he would either ticket them, or possibly more. But he would make sure they were deterred from ever doing it again. He caught some guys who were using someone else's boat (he knew the rightful owner). He took care of that problem. I doubt if they will ever use someone else's boat again, without permission.
You can tie them underwater (out of sight). That helps.