most sporting goods stores around here remove the actual sleeves from the boxes of higher priced balls. Some just use double security locks on the higher priced balls. Any time I buy balls from the store, I always check to make sure whats in the box is what I'm actually trying to buy.
Worked in retail before(at a dollar store) and you'd be surprised what people would actually steal. Things that cost as little as 50 cents or a dollar, they will still pocket them. Toothpaste, toothbrushes, all sorts of "beauty" products, switch bar code stickers, load up totes or coolers with various items so you only scan the cooler and they get whats inside for free...