I do not know why is everybody turning heads away from problem which exist. Only way how we can "ban" multi coin pools is fast difficulty retarget. It is already proven with SPT with dif. retarget every 2 blocks. If you do not believe look here https://bitcointalk.org/index.php?topic=259649.msg2960920#msg2960920
+1. For example, add a limit on the change difficulty no more then plus or minus 15%. Need to fix this problem, please.