@Intr3cpetion, Thank you for reporting this grief, I went to all 3 coords in the screenshots that you posted above. It seems all grief was done on unclaimed land. If you want to protect your things, you will need to rank up to "Homeowner" and claim the land where your base sits... also remember to /lock your chests, furnaces, etc.
I did find that 6 different people altered blocks at those coords, but since they haven't broken server rules, I will not be listing who or taking any action here. Please protect your things and be careful who you give access too.