I also remind people that laws change over time and that perfect crime prevention is actually a bad thing. The easiest example one can point to homosexuality. We now accept that people attracted to the same sex. But at one point in time in many places that was illegal. The last person in Canada to go to jail for being gay was in 1965, charged with gross indecency. But times and morals change so imagine if we had perfect police and everyone had to wear a camera at all times and every single thing you did was monitored and reported back to the police. No gays, no abortions, no alcohol, no speaking against governments or police, so many ways we would be oppressed. I am not saying people who harm children should free to break the law but the solution can not be to monitor everything every person does. The solution for me would be to teach people how to better set parental controls for their kids and to educate both parents and kids about dangers and online safety.