The pseudonomous owner of Bitcoin.org, known by his nickname Cøbra, accused several mining pools of centralizing the bitcoin network. He blamed Bitmain of controlling mining pools and threatening bitcoin censorship resistance feature.

The famous crypto-enthusiast Cøbra accused Bitmain, the world's largest manufacturer of mining equipment, in achieving control over 80% of the bitcoin hashrate.

According to Cøbra, Bitmain controls more than 80% of the bitcoin hashrate, although Cøbra also specifies that a more detailed analysis of the bitcoin network should be carried out to accurately assess the impact of Bitmain. His calculations are based on the belief that Bitmain controls the capacities of the largest mining pools, such as Antpool, BTC.com and Viabtc.

While Cøbra blamed Bitmain of centralizing the bitcoin network, another cryptocurrency, anonymous Zcash, also reportedly suffered centralization after Bitmain released its ASIC for mining Equihash cryptourrencies.

Earlier in June, the Zcash Foundation, together with the University of Luxembourg, conducted a network survey and found that, by the end of May 2018, ASIC mining accounted for more than 30% of the total hashrate in the ZCash network. At the same time, only four mining pools contributed about 87.5% of this volume. According to the Altpool.pro, within the first 2 weeks of June, ASIC miners managed to gain control of over 40% of the hashrate, and in the near future they will control more than 50%, making it possible to execute a 51% attack.