I think it would be cool you could add a feature in so they only had to click agree once, unless you made a change to that page then you could reset everyone's info and it would popup the page again for them. Otherwise they might get used to just scrolling and clicking okay without actually reading what is there.
I realize doing that would probably create a lot of extra work thought...
Koutaru - you might be able to disable the button using javascript.
This is a pretty sweet hack, I am planning on adding it in my forum soon.