Someone asked me about this the other day so I thought I'd just put it here.
"caveat utilitor" is latin for 'let the user beware' for those not versed.
If someone's profile is private you can still see their videos and pictures using a little trick.
Copy these to your address bar or middle click to open the hyperlinks in a new tab if you have text2hyperlink active in your browser like me.
PICS --> http://xhamster.com/user/photo/USERNAME/new-1.html OR favourites http://xhamster.com/user/photo/USERNAME/favorite-1.html
VIDEOS --> http://xhamster.com/user/video/USERNAME/new-1.html OR favourites http://xhamster.com/user/video/USERNAME/favorite-1.html
BLOGS/STORIES --> http://xhamster.com/user/USERNAME/blog/1.html
EDIT They finally fixed viewing other people favourite blogs/stories (about time) its still a little bugged as its stuck to one page though :(.
The favourites trick no longer appears to work for favourite videos when people have it set to "Don't Show" i.e. the only them setting. It used to work sometimes but recent evidence suggests this is no longer the case (it appears to always show their video uploads instead). It does still work for any other situation though (such as a private profile or friends only), assuming they have any favourite videos that is.
Copy their xHamster username and paste overtop of 'USERNAME' in the address bar
NB: can use this trick for lots of things on the internet (hacking of its lowest form) also you can use other words instead of new (such as rating) to order the galleries or videos by a different method. This will also compact he thumbnails since they wont be new line separated by date.
As Rockbitch said it can also show you their friend lists if you want to see it for some reason: