This message is almost always generated in response to a very specific error condition: you have attempted to open too many simultaneous connections to a single member site. The only other case affects only certain international web spiders that do not obey robots.txt. So, if you are a human being and you are receiving an "Access Denied" error from our network, it is probably because your browser is opening too many simultaneous connections.
This problem never occurs during ordinary browsing. All major web browsers currently do the right thing by default, and our network works with all of them. In the vast majority of cases, opening too many simultaneous connections happens because of a plugin, toolbar, or extension you have loaded into your browser that changes its default behavior. It can also happen if you're using something other than a browser to access your site.
Very rarely, this error can also occur with certain NAT gateways if several users behind the gateway all hit the site at the same time. This is most likely to occur if a device designed for home usage is being used in a business or organizational context with more users than it was intended to handle.