But...no. That's an assumption you are making about the solution - you are just assuming that the solution is banning pet dogs in public spaces. In which case, the people who pay for this solution are responsible pet dog owners. Maybe there is a way to think about the costs and benefits in a more balanced and logical way? So, for example, Metrolink Manchester banning pet dogs (no doubt the very cheapest and easiest solution to solving the problem of anti-social behaviour by a minority) - what cost did that have on others? What about the lonely old person, with a dog as a different kind of lifeline, who now can't get about? Who can't walk their dog in a park because they needed the Metrolink to get there?