great idea..... but you are looking at image recognition technology, and this will cost a fortune if you can find anyone skilled enough to produce this.
If you get this done let me know and I will buy it too....
As for user privacy - if they have nothing to hide they shouldnt object.
You are right, it will cost a fortune. So I decide to use 123flashchat, it's not cheap too. But it can make admins to view user's video chat . To monitor the porn video chat manly. And have a nice chat features. Just that a little expensive.
If you get this done let me know and I will buy it too....
As for user privacy - if they have nothing to hide they shouldnt object.