You do get a fair number of (usually) blokes who shoulder barge into you then give you the evils to try to intimidate you.
One sod even tried it with my ten year old recently. He was scuttling ahead (in school uniform) to get to the train and a grown man deliberately shoulder barged into him - a small boy - in a fairly empty station, then stopped all bristling to stand his ground/prove his manhood, or whatever. Bless 'I'm, DS swings around and yelled 'watch out, mate, I'm a black belt!' (which he is), which made a few people stop and turn. Bargey muttered 'owrite my man' patted him on the shoulder and scuttled off.
I've had words with DS about bargey people, mouthing off at people, and why he won't be taking himself to school by himself for the foreseeable.