TW Fake bidding

How to prevent TW fake bidding.

while on official PWI HT Server, I seen red colored system announcement, something like wraiths attacks on sanctuary region has wiped out the bid. and the land is again open for TW bidding for 6 hours after that. this happened after TW bid closing, and GMs identified that was fake bid. so only for that land bid was open where as others lands bid was closed and already scheduled.

can anyone guide me how we can stop TW fake bidding on private servers, or how we can do the above thing.

Regards,

Prashant