Any law that requires Super Heroes (or, really, anyone with superpowers) to be registered with the government in a national database (including the name and residence of each hero's Secret Identity) or face penalties. This originated with the Marvel Comics' X-Men in the form of the "Mutant Registration Act", where it provided a metaphor for discussing racial and/or communist themes. Since then, it has been used and re-used, and needs a fresh twist thrown in to be usable at all.