This tool can be used to check which servers are blocked by Mojang for violating the EULA.
It obviously cannot reverse the SHA1 hash, but the database contains all hashes of IPs checked below.
The base-index is from git.aperture.lol/projects/MOJANG/repos/blockedservers/browse/deleted-dict
(Reddit) Mojang is blocking certain servers as of 1.9.3 r2.
Follow this bot to get notified about new blocked servers:
Follow @Minecraft Blacklist