[djsumdog]

You're not "sort of safe" if you browse. The US has ISP reporting laws, as does Australia, South Africa, France and others:

http://chartsbin.com/view/q4y

It's a weird situation because in the UK, they simply block the content (no freedom of speech). In the US, we have freedom of speech so ISPs can't block anything. But they do have to report if you visit a site that contains illegal material or transmit it, plain text, through their services.

Child pornography is a strict liability crime to, so intent doesn't matter. Say you download something from /r/gonewild and the girl is 16, but she looks 20 to you. Too bad. You're not in violation of the law and can be put on a sex offender list.

Many people probably have illegal content without even realizing it. That's another reason why encrypting all your devices is so important.