Last year my neighbours' son's UK school set their 7 year olds a homework project to research sculpture. His parents asked for him to borrow a reference book on the history of the subject. It probably included pictures of ancient fertility figures, a "David", and various other famous sculptures.
I remember my university having an almost puritanical approach to the Internet. Basically anything that could potentially be smut was banned. Now this was a long time ago when dial up was king and there were far fewer sites on the net. I don't know how it worked, but basically If the site mentioned SEX or some such quite a lot it would be unaccessible. The only problem was that there were so many issues with it having false positives. The Sex Pistols was just one that caused difficulty especially for the popular music students. Restrictions were somewhat relaxed after the issues were pointed out.