As much as I appall griefing and hacking on non anarchy Minecraft servers/worlds that specifically laid out rules against griefing and cheating, I wouldn't just trust anyone with such a list because the problem is people can lie. I agree with the other posters here.
Trust your own experience and keep a close eye on friends you play with is what I would suggest.
Whitelisting is already a good tool to protect players from the troublemakers.
Why isnt there a section where people can post names of players that hack or grief so others can avoid them without having their world messed up?
Because blacklisting is frowned upon on every public forum. There's absolutely no way to know who's telling the truth.
Ubi bene ibi patria.
As much as I appall griefing and hacking on non anarchy Minecraft servers/worlds that specifically laid out rules against griefing and cheating, I wouldn't just trust anyone with such a list because the problem is people can lie. I agree with the other posters here.
Trust your own experience and keep a close eye on friends you play with is what I would suggest.
Whitelisting is already a good tool to protect players from the troublemakers.