The argument against the bike helmet law is that there is safety in numbers for bikers, and helmets discourage people from riding their bikes because they then perceive it as an unsafe activity. After all, if you need a helmet, how safe can it be? I don't do anything else that requires a helmet — I would never play full contact football, for example. I have a hard enough time trying to convince people that biking in the city is safe, and now they are passing a law stating that the opposite. This will clearly reduce the number of bike riders in the city.