As of today (1-May-2016), Mojang has introduced code that blocks client access to multiplayer servers that are breaking the EULA to the vanilla client.

So I have created this website with the help of @xBytezz to let server owners search their IP hash to check for blacklist status. Just type in your IP and it will search for you.

We have also created a twitter bot you can follow over at @BlockedServers which will post updates as they happen.

Much love - @minecoder
The source of this website is on Github and we currently hold some hashes in the database!