The system did not go live until 8:00 am ET due to request from USATF IT. The redirect to the LEARN site have been turned off and you should be able to set up a new account now.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .