Markymark,
We all make decisions in life and once made have to live with them. I think essentially public nudity today would be viewed in much the same way in 100 years time. The 'information age' is still relatively new and I think 'we' as a society are still learning how to manage and share information.
I would have an open discussion. If they have aspirations for a career in public life, they should be aware that at anytime in this career they may have to respond to such videos re-surfacing. How would they deal with their friends watching and talking about it? If they are comfortable with such potential situations and want to go for the experience.......then go for it!
Also, posing can be done in many ways. A porn shoot, personal xtube video or cam4 broadcast, stripping (either professionally or inpromptu call from the audience in a club) or even a nudist beach. Each of these has a thrill but shares 'information' in different ways.
Undie