Almost happened to my Mom one year. We were @ WM when the DVD players were like $25- $30. We had been there all morning, fought for 2 (we were sharing a buggy) of the few players they actually had in stock, and had moved on to the rest of our shopping.
My Mom is maybe 5'1" tall & this huge man at least 6'4" comes up and starts to take BOTH the dvd players out of our buggy. I heard my Mom raise her voice, turned to look for her & she was pulling them away from him. He was not giving up. I ran over there & between the 2 of us, we made enough noise that a manager came over & escourted the man from the store. He refused to give up, he was hollering at the mgr the entire way out the door! :-)
The nerve of some people! We fought for our $30 DVD players TWICE that BF!