Bike-share services are a good idea in theory. Riders can use their smartphone to pay to rent a bike, then leave it at their destination without having to return it. It saves money compared with car ownership, and reduces carbon emissions. In reality, certain parts of metro Phoenix have become a bike-share wasteland, with abandoned two-wheelers left anywhere and everywhere you can think of. It'd be kind of funny if it wasn't so annoying. The Instagram account @litterbikesofaz shares our opinion; its feed is jammed with photos of sad, discarded bikes (and parts of bikes) hanging from fences, lying in roadways, and dumped in canals. Next time you see one, take a picture and send it in.