Right. If what they do is not forbidden under existing law, no criminal charges can be brought against them. Of course, if they harm people, those people can

Right. If what they do is not forbidden under existing law, no criminal charges can be brought against them. Of course, if they harm people, those people can still file civil suits. And, it would be quite surprising if the "whole new kind of evil" managed to harm people without falling into a category already prohibited by law (i.e., assault). But, the point remains: you can't be charged for breaking a law that didn't exist at the time you broke it.