Power of base claims?

I had a question on how powerful the base claims on the CrundeeCraft server are. I understand players cannot break but can mobs still break blocks or is it not possible for them?

Mob griefing shld be turned off on all of our servers. There may be a few modded mobs tht can still break things. We suggest doing boss battles (since they are the ones that bypass the protections in most cases) away from your main base. That way if things go awry you wont suffer alot.