🍴 SPV Mining Forks the Chain at BIP66 Activation

On 4 July 2015, after the BIP66 softfork activated, roughly half the network's hashrate was SPV mining without full validation and built six blocks atop an invalid one. Bitcoin.org: "Some miners are currently generating invalid blocks... First fork: July 4 @ 02:10 to 03:50 UTC, 6 blocks." Affected miners lost over $50,000.