Lack of simple barn etiquette...picking up ytour horse's manure when they decide to decorate the aisle; leaving the wash rack hose on the floor, covered in mud and manure leavings; not cleaning up the wash rack when they get done with it. Taking MY equipment without asking or returning said equipment; in other words, stealing...I actually caught a woman, a leasee, in my tack box the other day. Fortunately it was more or less empty as I had just brought it back to the barn after losing my horse and pending a horse coming in for trial. I gave her the nastiest look I could manage but didn't say anything..she was very embarrassed though. I now make sure that if she is at the barn with me, I lock my trunk and tack locker before going anywhere. I do it anyway while I am riding.
She was in your tackbox??? The cheeky mare! I woulda given her a giant piece of what-have-ya.
The lads at my yard are always in mine, but I told them they could use whatever they needed so I don't mind.