When I was a teenager, I knew plenty of juvenile delinquents who would go around checking every car door, garage door, anything else to see if it was locked. If it was locked, they'd move on. If it was open, they would go thru checking for money, cigarette, booze, or anything of value. They would steal stuff they had no use for, just for fun. Or sometimes just do malicious mischief. Cheapo locks won't keep out serious thief's, but they will help keep some of the mischief away. I always lock my stuff.