I strongly encourage people to use Internet filters. We use BSafe Online. Yes, it can be annoying when you have to enter the password for sites you know are benign, but it is worth it.
I simply can’t understand how any caring parents would give their kids unlimited access to the Internet. The best illustration I have heard is this: Would you cram your kid’s unlocked closet full of pornography and then tell them not to go in there? Of course not. Then why would you provide unlimited access to all that and more on the Internet?