Cycling in Sydney Australia
Without wishing to sound snobbish (but probably failing), they look pretty cheap and not very modern. They may have even come from a council collection.
What makes you think they have been stolen?
I saw a junkie neighbour riding one and well junkies have a habit of stealing bikes. This area has a very high bike theft culture going on and i would hate it to happen to me. Community service :0) They are pretty modern for our area. Someone would be missing them. Anyway called the police anonymously :0)