BlockBeats reports that on November 26, The Mining Pod blog revealed that U.S. Customs and Border Protection (CBP) is detaining certain imported Bitmain Antminer machines at U.S. entry ports, with the involved equipment being Bitmain's Antminer S21 and T21 series, which are Bitmain's latest ASIC miner series.
Sources say that the FCC and CBP have not targeted other ASIC manufacturers such as MicroBT or Canaan. Aside from revealing that the FCC requested a freeze, U.S. Customs and Border Protection did not provide the affected parties with specific reasons for taking this action, nor did it specify how long the goods would be detained.