Just a note, there is a possibility that the person you replied to is comfortable with circular logic about why the behavior is not controversial under the supposition that "the law is the law." This may be a semantical discussion about why it is not "retroactive" in a legally damning sense, despite the similarities of the distinct ability to civilly and criminally sanction somebody for something they did in the past. Long before representatives of the government decided that person's prior actions would fall under their jurisdiction.