Dammit, I just Googled "Sesame Street" and after sifting through the first several pages of hits didn't find ONE porn site. Guess that "nothing but porn sites" claim of Todd Z's is a little alarmist.
As for Fer's statement that search engine are able to filter out inappropriate material, all I can say is they do the best they can, but none claim to be or are even close to 100% blocking.
Let's suppose you are searching for information on breast cancer, or researching statistics on child pornography....one missing or one added search keyword and you get VERY different results, and how is the search engine supposed to know that you intended a G-rated search vs an R or X rated one?
Yes, I do think web site and web browser standards should be defined and adopted that will allow filtering, but even if they existed today (e.g. use of a .sex domain name; or meta-tags that include rating information, etc), than there will always be those trying to push their wares that work outside of the standards.
It was for this very reason that the FCC supeoned Google and requested one months worth of search strings entered by its users (redacted nonetheless). The last I knew, Google wasn't complying. The intent by the FCC was to show that even when NOT looking for porn, porn looks for you!
TJR