We spent a few days on Waikiki beach in February and some sad loser was building sand walls not just for himself but also another for his mate who turned up three hours later and said he did't want it.
I once had a fight at a hotel on Tobago with a german over a sun lounger. Because it was on the lawn outside his room he thought it was his. Some swedish chap used to get down to the beach every day at 6:30 just to bag his coconut sunshade. One day I woke up at 6:00 and was very tempted to go and grab it before him, but I thought that would be childish.