Back in the 90s at Hunter I had a pair of skis taken off the rack by someone else at lunch time, they left their similar skis near by. Eventually got them back, nothing stolen.
My son had a nice pair of Leki Spitfire Vario poles stolen at Whiteface last year. Pure theft, mid afternoon someone scooped them up and stole them. Distinctive poles, no mixing them up, no similar poles left nearby.
A few years ago my daughter had poles taken at Whiteface also, Bear Den. When everything was gone at the end of the day there was a pair of rental poles abandoned by where her poles were. Mix up? Maybe....but her poles weren’t turned into the rental shop, so who knows.
Bottom line, while having something stolen just sucks, you have no one to blame but yourself. I grew up always separating my skis/poles. Then I got a lock. Over the years you become complacent, stop separating/locking, my kids never got in the habit....then boom! Just separate or lock up your shit, we do now.