Yep, because if someone claims something might be bad for them, we should restrict access for everyone! By the way, hacker news makes me slack off at work, so I'm looking forward to the law that forces ISPs to block it by default.
BTB, I am not talking about blocking porn, just users should go through a password wall. Also the users should be able to change this default setting if they like. This is not much different from the password protection for adult content offered by many cable tv companies.