Yeah, you can probably find a study to back it up

But it’s a well known joke even in gun communitie that those are just “rob me stickers”.

Anyone with those stickers is an idiot with a gun. So rational people avoid them and the owners think it’s because they’re tough. Meanwhile criminals check to see if there’s a gun in it when it’s unoccupied or follow them home and rob them when the truck (it’s always a truck) is gone.