1. get griefed (a thing what never should be happen)
2. if you get griefed got a golden pickaxe

3. place a block on the place where the destroyed block was
4. right click with the golden pickaxe on you own created block
5. be happy to see tho destroyed it
http://free4u.kilu.de/incoming/70638678loglbock.png
Thanks on this place to our little griefer friend wojciowwww who tried to destroy my trap