Only the naughty ones are password protected (you have to ask to get permission). Most people have links at the bottom of their posts, or in their profile, to the website where they have uploaded their pics. Just click away!
We set up the fotki site of temptationpics for people to post their pics that they may want to share with their TTR friends but don't want them to be totally public. So far it has worked well with tons of pics Many others have their own site on fotki or photobucket or flickr. Any R rated pics on the public part of those sites tend to get shut down so password protection becomes the best solution. It also protects the innocent and not so innocent.