I have covered way too many issues with porn on Google. But let me show you two recent examples that impacts children.
(1) A Google Web Search Help thread has a report from a searcher who is disgusted that Google will not remove a pornographic image of two girls for a search on [babysitter]. What upsets me most is that this person said he/she reported the image three or four times. Of course, I have no way of verifying that, so I am going by this person's word but nevertheless, the image should not be there.
If a kid goes to Google to find a picture of their babysitter, the last thing you want coming up is a picture of two naked women on a bed together. Here is a censored image to prove this comes up with normal moderate SafeSearch on:
(2) A second thread at the Google Web Search Help forums reports that when you type in "little girl" into Google Images search, Google auto-suggests "little girl no cloths." Here is a picture:
Yes, these suggestions are pulled from what people search for but Google does censor certain types of suggestions. We had issues like this before, such as with little kids having sex and other porn examples. Google does censor adult oriented suggestions and most people agree that is what Google should do.
For Google, this is a constant battle between those trying to inject porn in their search results and Google trying to keep their search results clean. It is not a fun battle.