I too have experienced someone just helping themselves to my things at a
vet check. In my case, I was riding a 50 mile ride without a crew. I
came into the stop, and since it was cold (a November ride) the first
thing I did was look for my blanket. I couldn't find it anywhere! It
was not with the rest of the my stuff the ride management had brought out
to the hold. So instead of being able to work on getting my horse down
for the P&R, I ended up walking him all over camp to find my blanket.
Finally, after much time goes by, I finally gave up and got in the P&R
line. And there, one the horse being checked out was my blanket! I
asked the rider why she had my blanket and she just shrugged it off -
said that her horse was cold and my blanket was handy. So I know
firsthand that there are riders out there who think that everyone's
belongings are "community property". I was pretty discouraged by it - I
don't have the luxury of a crew - and if I have to have one just to
"guard" my belongings I won't be able to participate. Fortunately, I
think riders like the one I am describing are the minority.