Mining Pool operator BTC Guild says that if implemented, the proposed guidelines put forth by the New York Department of Financial Services (NYDFS) may force it to shut down. The only other alternative, it says, is to "operate illegally and hope they're ignored".
The announcement cites two reasons: (1) The proposed regulations require a pool to obtain personal information about all its users, not just those in the US. Since this is not feasible, it is impossible for them to legally operate in the US. (2) The costs of compliance will be prohibitively high, exceeding "the amount of money the pool has generated since inception."
Usually, the pool says, it guarantees a minimum of 3 months' notice before closure. However, this case would be exceptional with only 45 days. The regulations call for the cessation of operations prior to the new rules coming into effect, and NYDFS has given 45 days to review the proposed rules.
The announcement starts off by reminding users that the pool is not a bank, and therefore miners should make periodical withdrawals to reduce their risk of loss.
BTC Guild describes itself as "one of the oldest remaining mining pools". It typically commands about 5-10% of the total network Hash Rate .
