While many of you make a good argument, I think the majority of you have blown this regulation WAY out of proportion. The two most inflated analogies are:
a) This isn't like taxing car manufacturers because cars sometimes wreck. It would be like taxing a car manufacturer that designed its cars to be likely to wreck, weaseling their way around regulations in the process, and the tax money going towards medical bills. Porn sites intentionally try to get people to visit them accidentally, regardless of age. In fact, there have been porn sites with names such as "dinsey.com," which is blatantly meant to attract kids.
b) This also isn't like censorship or communist China. It's a TAX on SALES, not a forbiddence. Cigarettes have extra tax because they're harmful, but they're still available. Alcohol has some extra things like liscences and regulations, because it's harmful, but it still sells. Why shouldn't pornography, which is harmful to minors' psyches, have extra tax and regulations put on it, rather than running rampant, like now?
While I do think the responsibility is ultimately the parents', porn sites spend a lot of effort to make sure they get around content blockers, and like I said, many porn site hits are total accidents. Porn should, at the least, be regulated so that you can surf the internet without seeing it if you don't want to. Typical Dem reaction is to tax and make a program, which, in retrospect, isn't that good an idea. Drawing attention to the problem, though, is a good thing, just like it was with spam.