Yes, and it was not particularly pleasant.
There was this one guy in my first year of university (let's call him TP... because that's what his initials are!) who sort of clamped on to the friendship group I was a part of like a limpet. At first we were all "cool, a new friend" and he started doing stuff and hanging out and other friend-y stuff. Then TP started acting weird. Not 'serial killer'-weird or anything, but he'd start coming to things where he wasn't invited to (not because we disliked him, but not all of us invited everyone to everything), have these mood swings and our original opinion of him as 'kooky' slowly morphed into 'someone we don't want to talk to'. So we decided to give him the message that we didn't really want to see him slowly, by gradually inviting him to fewer and fewer things. But that didn't work, and he was in our face all the time. Eventually, we just decided to cut him off; no phone calls, no texting, no Facebook, nothing. The tipping point was this time when we were all going out to dinner and TP saw us leaving the uni accommodation. As one would expect, he started following us. Instead of stopping like normal, socially acceptable human beings, we all ran away instead. It was kinda monstrous at the time, and I feel bad about it to this day... but it did the trick. Haven't spoken to him since. (He's fine, by the way. According to Facebook he's a consultant, so good for him!)