Hackers steal $100,000+ worth of BTC from engineering manager at Crypto Custodian BitGo. Sean Coonce, engineering manager at cryptocurrency custodian BitGo. According to the post, Coonce had over $100,000 siphoned out of his account on cryptocurrency exchange Coinbase in under 24 hours. Coone details SIM swapping, a practice that sees the attacker maliciously requesting a telecommunications carrier to redirect the traffic of a mobile phone number to a device over which they have control.