I worked in retail mgmt for many years. We always kept our backrooms locked and allowed very few people in. This was to prevent people rifling through personal belongings, seeing the schedule posted on the wall sales figures,etc
One regional director I worked with liked to boast how he would make an excuse to get into a competitors back room and then see all of their confidential notices, sales, schedules, etc.
It was very commone for travelling gangs of shoplifters to hit one store after another and steal wallets and money.