Nope, can't say I have ever been personally even threatened in the street, not even in the past 3 and a bit years of stumbling around Manchester drunk! (I should say, there have been moments I have been sober too, honestly).
I think the two closest incidents that could compare to a violent encounter where both cases involving someone slightly psychotic who wasn't after me or my things personally.
First was while out for a friends birthday around Essex somewhere (can't remember the exact details.. i just hopped in a car and went where I was told..), we were on our way home from whatever pub/club we had been too and a guy with a police style baton crossed the road towards us threatening to bash the heads of the two girls that were with us in saying they were "scum, all of em", this was followed by two of us turning round and telling him to leave* (*might not be the exact words) at which point he slumped down against the nearest brick wall and started crying. We went home...
The second was in Stafford when I was a student, we were on our way home after a night in the student union, the walk involved going along a long straight, nearly always deserted, a-road, with hedges all along its edge. So there we were, bout 3 in the morning, all quite drunk and suddenly this French bloke (very clearly drunk) pops out of a hedge (!), I'm not kidding he just kind of glided out like a Jedi or something. Anyway he stood in front of us and quite calmly stated "I think I should go with those ladies, you can't be trusted" then he tried to put his arm around em (our group was 5 guys and 2 girls).
So er.. yeah, the girls didn't take too kindly and ya know.. started hitting him, at which point he slinked back a bit and we asked him what he thought he was doing, so he said (and I very nearly quote) "I need to take these girls away from you, you're going to rape them or something". At this point we all just laughed and walked on, pushing past him, gave it a few seconds then looked back to see if he was following, but no, he had disappeared back into the hedge! Odd fellow.
Anyway, those are the two "confrontations" I have ever had in my life that stick out. Maybe I've just been lucky, or maybe I subconsciously avoid going to places I think will be bad for my health?