Have any of you given a warning to a friend's boyfriend/girlfriend or date that you'll hurt them?

[Anonymous]

Like warning them as in if he/she ever hurts your friend, you would hurt them back hard if something bad happens. If so, is it worth to give a warning so don't won't treat your friend wrong/bad?

(One of my friends have been seeing this guy online who apparently lives really far from another state and I have a gut feeling that he's no good, they haven't even met yet and they've been talking online due to Covid)

[Avicenna]

Nope, not something I'd do