F2Pool Co-Founder Says OFAC Transaction Filter Disabled – For Now

Bitcoin developer concluded that F2Pool likely filtered OFAC-sanctioned transactions

Wang Chun, the co-founder of F2Pool, has said a bitcoin transaction filter patch will be disabled in what appears to be a move responding to questions on F2Pool filtering transactions from OFAC-sanctioned addresses.

Earlier this week, anonymous bitcoin developer 0xB10C wrote in a blog post that from September to October, six blocks missing OFAC-sanctioned transactions were identified by the developer’s miningpool-observer project. Four of the blocks were mined by F2Pool while the other two were mined by ViaBTC and Foundry USA Pool.

Based on the methodology described in the blog post, 0xB10C concluded that the sanctioned transactions missing from blocks mined by ViaBTC and Foundry “are likely false positives and not [a] result of filtering,” adding that “the transactions missing from F2Pool’s blocks are, however, likely filtered.”

The developer raised further questions as to “why F2Pool, a pool with origins in Asia, is the first pool to filter transactions based on US OFAC sanctions.” F2Pool is the third largest bitcoin mining pool. The real-time hashrate connected to the pool has not experienced any material decline over the past three days.

In a now-deleted quote-tweet responding to 0xB10C’s findings on Wednesday, Wang seemingly confirmed the transaction filter, saying:

“Why do you feel surprised when I refuse to confirm transactions for those criminals, dictators and terrorists? I have every right not to confirm any transactions from Vladimir Putin and Xi Jinping, don’t I?”

Wang said in a subsequent tweet that [F2Pool] “will disable the tx filtering patch for now, until the community reaches a more comprehensive consensus on this topic.”