I've noticed for years that many (often younger) server owners and players fall victim to so-called Griefer, which destroy their servers. If this has no backup, the server is gone forever.
My idea would be to create a website with a grieferlist. Server owners can enter Griefer there (with evidence) and others can ask for specific player names if they have been reported in the past.
Is that legally allowed? Does a player name also fall under the data protection law? I live in Switzerland, maybe the legal situation is different here.
So the player name is not legally protected, and so a general slate list on a Minecraft forum or something is already a good idea.
With your idea you are a few years late.
http://www.mcbans.com/
Something like that already exists: http://www.mcbans.com/
But to answer your question: Yes you can do it, it is allowed.
