Bitcoiner spends $3 million on transaction fee

A Bitcoiner making a large transaction ended up spending 83.64 BTC (~$3 million) of the 139.42 BTC (~$5.1 million) transaction on transaction fees, effectively spending $3 million to send what ended up being a $2 million transfer. This apparent error has become the largest transaction fee in Bitcoin history.

A person then claimed on Twitter to be the owner of the wallet, verifying the claim by signing a message from the wallet that paid the fee. They claimed that they had been hacked, and that an error on the attacker's part led to the huge fee payment. AntPool, the mining pool that mined that block and earned the huge fee, later agreed to return the fee, though it's not clear if or how they verified that the person to whom they're returning the fee wasn't in fact the attacker who had obtained control of the wallet.

A similar fee overpayment incident occurred in September, when the Paxos crypto firm erroneously paid a $500,000 fee to send $1,865. They attributed the huge fee to a bug in their software, and the F2Pool mining pool (who had mined the block and received the fee) opted to return the overpayment.