When a new user log on, he gets the terms of conditions page. He then gets the option to select "I Agree" and "I Disagree".
If the user clickc "I Agree" then he is forwarded to the homepage.
If the user click "I Disagree" he is asked to click on "I agree". There is no option to totally disagree. ie. if the user really wants to disagree, he/she should be taken back to the logon screen. Not forced to agree via a popup saying he must agree to continue.
It should stop the log in process and IMHO make his account inactive, but they might want to consider leaving the admin room to alter that.