Ummm. In the U.S.
In MANY other places in the world, it is the opposite. I've seen frontal nudity at 8-9 PM on the T.V. in Spain, Italy, Germany and France. But violent movies (e.g., "clockwork orange" or the original "Texas Chainsaw Massacre") didn't even used to be available for private sale in the original, U.S. version in many places overseas. (The original versions often sold for over $200 on the black market.) Makes me glad I saw "Basic Instinct" for the first time in a theatre in France. There are also places where BOTH is taboo (e.g., China).
And in many locales, BOTH violence and sex are taboo. Please don't allow American puritanical views to define an international sport.
Edit: I like the ideas expressed further down, of having "self limiting" preferences to control the "types" of waymarks that appear. Sort of like a "V-Chip" for Waymarking. There could be categories such as "nudity/sex/adult themed" (e.g. strip clubs), "violent themed" (e.g., crash sites "upload photos!"), "scatelogical themed" (somebody already submitted a "poo" proposal, I believe).