The London Congestion Charge is enforced by comparable cameras. If you've noticed a recent profusion of eastern-European registered cars in London (especially Lithuania, which for the size of the country must have half it's cars in London now) it's because the system cannot pursue them for payment with the Lithuanian registration authorities, yet under EC law they ae perfectly OK to be used in Britain for as long as they like (also evades road fund licence). Presume this goes for speed cameras as well.