There are several contracts whose internal Tx have only suicide calls from the same contract/user address over and over again. What is the need of having multiple calls?
SUICIDE opcode uses negative gas because the operation frees up space on the blockchain by clearing all of the contract's data.
This negative gas deducts from the total gas cost of the transaction, so if you're doing some clean-up operations first, SUICIDE can reduce your gas costs.
Probably all contracts must have been cleared the same user, hence you could see such transactions