Beyond molested bicycles, street cleaning vehicles and bad wiring, shopping carts are highly ranked in my list of intriguing city devices. One of the reason is because there is always a small proportion of carts that are stolen, abandoned or used or other purposes. Some examples easily comes to mind, see for instance how this bunch of homeless people in LA use the cart:

OR, more intriguing in Madrid, I stumbled across these 2 guys who collect steel material on the street before selling it somewhere. The carts shown below served as a convenient way to carry steel stuff before heading to a buyer:

BUT it's certainly the abandoned shopping carts like that one encountered yesterday in Geneva, which ranks first in my list of cart behavior.

Abandoned carts always makes me wonder that there are strong design opportunities for micro-distance devices like this in our contemporary cities.