Some new users like him setting up some sexy or adultary photos as their profile picture.This SE site was not only viewed by adults but also by the minors.
So my question is that SE provides any restrictions on setting up this kind of profile pictures by new users? I think currently not but in the future.
My opinion is "New users can change or setup their profile picture on only they got 100 reputations".Like a privelege.
100 rep Access to change profile picture