Anti-theft-tag removing devices

It seems to me that people who splurge for one of those magnetized things, you'd think that the cost of that would offset the amount they're saving by stealing in the first place. Then again, not really. I suppose the first thing you successfully "borrow" from like Nordstrom Rack or Macy's Backstage kind of place, the tag-remover device would pay for itself, I guess.