They use a special filter called the Octonet filter to block VPN, TOR and Proxy services because they cant block enough specific IP addresses when they dont want someone to post truthful things that make them look bad, so they block whole domains when they can.
800notes is nothing more than a money-maker from ads on the site and promoting that they "expose scams" is a scam in itself, they dont expose anyone, its supposed to be a "Phone Directory", but its just a place anyone can post anything they want.

800Notes has exposed a lot of scammers. Occasionally one or more try to shut down the site with a Distributed Denial of Service attack. That often works short term, but is eventually resolved.

I am not a member of site management but I am a frequent poster. Those DDoS attacks block me out, too.