“For better or worse, defensive designs limit the range of activities people can engage in. They can also create real problems for the elderly or disabled. Some of the goals of unpleasant designs can seem noble, but they follow a potentially dangerous logic with respect to public spaces. When supposed solutions address symptoms of a problem rather than the root causes, that problem is not solved but only pushed down the street to the next block or neighborhood. Spikes beget spikes, and targeted individuals are just moved around without addressing the underlying issues.”