There's an announcement on the Social Strata help forum that most Hoop.la sites (which includes this one) will be down for maintenance work. In this country it's forecast to be for some time between 3am and 7 am on Thursday morning.
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 .