Personally their isnt ways to stop them until after the fact that they griefed. Most can be prevented using WorldGuard, but can also be rolled back via BB or Backups. Otherwise you could uphold a whitelist, only allowing trusted members in.
In another standpoint,
We would have to worry about griefers if forums like these allowed the posting of a public ban list exploiting their ips (Statics and proxied) to the whole community, so it saves new server owners the pain of having to learn to counter it and prevent the development of paranoia like most server owners have.

Lol thx

SoulStealer

TheAsteriteAgain.
FUDGE THAT. GRIEFER. THE HELL UP. AND. GO. TO. HIS HOUSE. AND BEAT THE FUDGING CRAP OUT OF HIS COMPUTER. THEN GO BACK TO MINECRAFT. IF HE SHOWS HIS FACE AGAIN STEAL ALL HIS CRAP AND PUT HIM IN A 5 BLOCK THICK OBSIDIAN BOX FOR AS LONG AS IT TAKES.

Thats how i deal wih them.

Watch the language!

I've heard the F-bomb in PG-13 movies. Just saying.

Or see the dome Pokin out?

They would have to A. See you B, Glass Texture Pack C, Maps? D, Or Mods

Well that works too... But wouldnt they dig under it too?

Just like dig a hole... Block it up.... And build down there.... Not much.... (Also for a Great back up build a Obsidian dome)

/ban then rebuild. Problem solved.

Ok sry just got LITTLE emotionall

TheAsteriteAgain.
FUDGE THAT. GRIEFER. THE HELL UP. AND. GO. TO. HIS HOUSE. AND BEAT THE FUDGING CRAP OUT OF HIS COMPUTER. THEN GO BACK TO MINECRAFT. IF HE SHOWS HIS FACE AGAIN STEAL ALL HIS CRAP AND PUT HIM IN A 5 BLOCK THICK OBSIDIAN BOX FOR AS LONG AS IT TAKES.

Thats how i deal wih them.

Watch the language!

Again.
FUDGE THAT. GRIEFER. THE HELL UP. AND. GO. TO. HIS HOUSE. AND BEAT THE FUDGING CRAP OUT OF HIS COMPUTER. THEN GO BACK TO MINECRAFT. IF HE SHOWS HIS FACE AGAIN STEAL ALL HIS CRAP AND PUT HIM IN A 5 BLOCK THICK OBSIDIAN BOX FOR AS LONG AS IT TAKES.

Thats how i deal wih them.

EDITED because that was not PG-13 Language.

Oooorr stay home, hide in your MC closet, and when a griefer comes nocking, JUMP HIM AND BEAT DA LIVING SHIT OUTTA HIM!!!! also hide your chest and use all those programs too.

Make a Backup and let them reek havoc.

I ain't a griefer BTW

Use Anti-Greifer Plugins ...

Get the /cprivate plugin.

We're called GRIEFERS god dammit!

GRIEFERS.

Also you shouldn't battle us, that takes out the fun in minecraft.

As stated above, use bigbrother. Bigbrother is a bukkit plugin that logs everything someone does. It allows you to rollback or undo a players action. Also, if you are the owner of a server, I would recommend you to find moderators, admins, people who you can trust. Then, give them the power to ban people and use bigbrother to find who the culprit. That way, when you can have the work spread between several people. I

If you are a player of a server, just be smart. Lock your chests if the server that you play on allows you to. If you cant lock your chests, than be smart to hide your chests. put it underneath the floor and cover it with a block. Just be smart

I say hide your home.

You don't battle them. In my opinion, if it is a SMP server, you let them grief, as that is kinda what SMP is about (creepers grief after all, right?). Then if you have iConomy you can let people buy protection for their homes/ creations. This also stops playing from whining all the time that "That newb over there just destroyed my house, ban him".

Killed 2 birds with one stone right there.

Well, you can start by learning your vocabulary. The term is 'greifing' as in, intentionally causing other people grief.

Then, you may want to install a backup program (I use Craftsave, used to use Simplesave). You may want to look into promoting more OP/Admin and setting up a whitelist to keep them out, although those can be troublesome.

Bigbrother