Geocold”, an “ethical hacker”, announced on Reddit that he would be choosing a coin on which to perform a 51% attack for “educational purposes”. After a failed attempt with Einsteinium (EMC2), the hacker eventually settled for Bitcoin Private (BTCP) and executed the attack live on twitch for everyone to see.

The attack, however, did not go down smoothly. Over 750 viewers were tuned in when the twitch platform pulled the plug. Banning Geocold due to “attempts or threats to harm” others, the incident was most likely the result of multiple reports from members of the Bitcoin Private community. The hacker then moved to stream.me but was again blocked after 15 minutes. When the second stream died he already had a majority of the hashrate and was able to mine BTCP blocks at will. He later reported on twitter:

Update on the stream. Got banned from two streaming platforms fairly quickly. I'm going to try to find a platform where I can be assured report spamming won't work. If not I'll just post a video on youtube. But attack wise: We got ~70% of BTCP's network and I was about to fork it.

Aside from the stated educational purposes, Geocold’s motive was apparently to demonstrate how easy it would be to perform a 51% attack on altcoins with little market cap but a recognized reputation.

His initial plan was to attack the Einsteinium (EMC2) network. However, when the scheduled date for the attack arrived – October 13 – the EMC2 community had deliberately acquired huge amounts of hashpower in order to prevent the attack. Having predicted this, Geocold already had a contingency plan to pick another altcoin and elected Bitcoin Private as his next “victim”.

Geocold stressed that they performed an “ethical hack”- without benefitting financially, and could have chosen to fork the blockchain but chose not to:

Worth mentioning. By “I was able to fork it” meant  I could have. I elected not to so that I could save it for a future stream but I had a longer blockchain and was ready to go.