Bitcoin Miners Ditch Ghash.io Pool Over Fears of 51% Attack"Bitcoin miners around the world are starting to leave the Ghash.io bitcoin pool following a significant increase in the pools hash share.
According to Blockchain.info, Ghash.io accounted for more than 42% of bitcoin mining power a day ago, but over the past 24 hours its share has dropped to 38%. ..."
http://www.coindesk.com/bitcoin-miners-ditch-ghash-io-pool-51-attack/