Bitcoin developers monitoring have found that F2Pool is suspected of intentionally filtering transactions involving addresses related to OFAC sanctions

ChainCatcher message, Bitcoin developer 0xB10C posted that six Bitcoin transactions from OFAC-sanctioned addresses were recently detected as not being mined by some mining pools, which may indicate that these transactions were intentionally filtered. In September and October 2023, the tool found missing OFAC-sanctioned transactions in six blocks mined by ViaBTC, Foundry USA pool, and F2Pool. After investigation, 0xB10C believes that the missing transactions in ViaBTC and Foundry USA pools may be false positives rather than due to filtering.

However, the missing transactions in four blocks from F2Pool are likely to have been intentionally filtered. These transactions are all large transactions that consolidate multiple inputs into a single output, with at least one input coming from an OFAC-sanctioned address.