Facebook.Com Question!!?

Hey all im gonna tag this in relationship area because the population is huge...

Anyway on my Facebook and on Vk.ru a lot of other men seem to always post naked girls and so on and add pictures of naked girls all the time. Awkward I meet must of these people in real life nice good person but on internet they seem to be..well you know.. but why is this? And some girls even do the same of them or other girls... Why is this???? Like didn't their parents teach them anyway better?

Now don't get me wrong I like ladies to but im old fashion I was raised in old ways my father and mother are in 60's and im 21. but I would never do this. but in the end don't they feel shame? or weird or awkward or do they in brace there pervert side....? like sure I guess do your yank yank in private but why always post it on facebook wall and such??