IME these types of questions tend to get closed.
That said, I'd be opposed to flagging questions based solely on (perceived) legality.
If I had moral objections to it I just wouldn't answer, if I felt strongly enough I'd leave a comment, and let it go–not my business unless I'm a named (or likely) target. IMO flagging based
Flagging on quality, locality, and the other standard flagsstandards is enough: if they don't apply, don't flag.