Privacy-centric blockchain network Grin (GRIN) is undergoing a 51% attack, an event in which a miner (or miners) acquires more than 50% of the network’s mining hash power and takes control, according to a notice at the bottom of the Grin protocol’s website.  

• According to 2miners.com, which is responsible for 19.1% of the current hash power on Grin, the unknown miner(s) grabbed control of 57.4% of the network's hash power.
• While the attack is underway, the protocol is warning users to wait for extra confirmations on transactions for payment finality.
• Grin, which was the first cryptocurrency to test privacy protocol MimbleWimble and drew an estimated $100 million in venture capital to mine it, was once called “Bitcoin 2.0.”
• GRIN coins were down 2.23% to $0.235 at press time.

See also: Ethereum Classic’s Terrible, Horrible, No Good, Very Bad Week