Slavery as a condition of web page use? I found a web site where a hidden term is that you agree to not disobey any employee of the company. The interface is set up so it is not possible to see the terms and conditions until you are already using the site. 

Hidden number 27: obey!

Nice try, Satan.

Actually, from the point of view of the simulation, we probably all agreed to obey already. The terms of use in here may include obeying the current laws of physics, for example.