Quote from: cbcbct on January 11, 2019, 02:34:05 AM

Quote from: tabas on January 10, 2019, 11:13:56 PM

Quote from: estenity on January 10, 2019, 10:34:45 AM

51% attack confirmed by exchange gate.io
see paper on cointelegraph

Here are the links
Crypto Exchange Gate.io Confirms 51% Attack on Ethereum Classic, Promises Refunds
Coinbase: Ethereum Classic Double Spending Involved More Than $1.1 Million in Crypto

Dominant hashrates in one pool will highly result in potential Replay attacks.
As someone stated above, the fees require to hire enough hashrates from NiceHash to make attacks become cheaper recent months, due to drops of both bitcoin and altcoins.
Consequently, more and more attacks occured within last several months.

this is an inherent weakness of POW.