The Easy Griefer Votekick
A good idea to counter griefing is that a notification comes up in the chat box of that your placed blocks are being destroyed and the nickname of the person who is destroying your blocks.
Only then a /votekick command can be used on the person griefing your blocks with the reasons :"grief griefer griff graff gref grif grie griefing giraff griefin (including capital versions)" etc.
If you votekick a person which is griefing your blocks for griefing, and you have been notified about it, the votekick only requires 2-5 /y votes (Also called The Easy Griefer Votekick). If you votekick a person who didn't grief your blocks, then it requires more than 5 /y votes.
This can be coded in a pyscript, and would give more power to the griefed. To prevent those being griefed acting like a Griefer Patrol (with that I mean people shouldn't votekick others for griefing if they destroyed only 1-5 blocks, that shouldn't be classified as serious griefing), a server-side limit should be set for the amount of blocks that need to be destroyed in order for The Easy Griefer Votekick to be applied.