they have been stealing bikes since the invention of the bicycle

their were horse thieves
then thier were bike thieves

bikes are one of the easiest stolen items to "move"
both usable and sellable
there is a used bicycle market

bicycles may be at the top of the list of stealable-sellable items
even above stereos

man steals bikes in Fort Myers Florida
www.nbc-2.com

don't buy stolen bikes
it perpetuates the "cycle"