They can be annoying when they go off when nobody really stole anything, but the cashier forgot to remove that little thingy from their purchase. Seems to happen constantly at Walmart.
I hate to sound like a goody-goody, but shoplifting is very wrong. It irks me when people steal little things that don't cost much and justify it by saying, "It's not like I killed somebody" or "The stores deserve it because they rip us off with their high prices". I also don't like it when an elderly person shoplifts and people in the store actually let them or show sympathy and think they're only doing it because they're poor. I saw that once on that show What Would You Do?.