I have only seen it happen once or twice in-person, but I've run across it multiple times online. Had one guy, known for being awkwardly friendly (as in, had a motive) with the women in the group, even try to invite himself to stay with me multiple times while he would "be in town" and even when others would say "Dude, please stop," he would retort with "Once she meets me, she can decide!" Wouldn't let up on it, even after personally shooting him down.

Found out later he was doing this same thing with other girls, too, and was kicked out of the group.

Can I get a clarification on the downvote, given that the parent asked for examples and I provided one? I've elaborated on the specific situation.

I think they were asking for examples of white-knighting, which is not what your story was about. Not that it wasn't worth sharing, it just didn't answer knowtheory's question.

I think you provided a counter-example, instead.