Invisible blocks are well... blocking

Right, well I am working on a base for a group I am with and some random person left full sized invisible blocks all over the building site. He is never on and doesn't respond to my off-line messages for removal of the blocks. I don't own the land I am building on so I can't return the blocks to him and the owner is almost never on and hasn't logged on since the blocks were placed. It might be old group war issues because this group is being restarted from an older army group. I don't expect an form of punisment to be issued to the blocker just asking for block removal and please do not delete anything from the base as i am having linking issues and can't seem to get a copy of the whole thing. The coordinates to the base are: Nimrod Yaffle 222, 53, 106. Thanks for the help.

Hello Thorin. Nice talking to you in world. As you now know, the land owner needs to address this issue.