Is there Wordpress or similar tools that any visitor can modify and persist?

I am looking for a way to have pages on my wordpress site, where any visitor can make some changes, and the changes become global and persist.

More specifically, I want to have a way to distribute some sensitive data, and I want to make sure the visitor has gotten the data. So something as easy as having a button that when clicked reveals some text would work. I need a way to know if the button has been clicked or not.