Ever heard of the band "Nothing but Thieves"?
Yeah, it's called RobberBand.
Alright listen up, buttercup. This joke is all about wordplay. "Nothing but Thieves" sounds like "Robber Band". It's funny because robber bands steal things. I know you have a hard time putting those two ideas together but just follow along ok? It's all about how similar the two names sound. You probably get tricked by that kinda stuff all the time, huh?