It's not an issue in some parts of London (City and Camden for example), where they've marked out on street parking bays and worked with the companies to ensure that there are fines / bans for those who don't use them. The problem here is that as much as people don't like them on the pavement, many would not like them on the road either (loss of parking). Personally, I would make sure that every street had at least one space for a car club car, and one or two for hire bikes - on the road (not the pavement).