Mt. Gox
On 22 February 2013, following the introduction of new anti-money laundering requirements by e-commerce/online payment system company Dwolla, some Dwolla accounts became temporarily restricted. As a result, transactions from Mt. Gox to those accounts were cancelled by Dwolla. The funds never made it back to Mt. Gox accounts. The Mt. Gox help desk issued the following comment: "Please be advised that you are actually not allowed to cancel any withdrawals received from Mt. Gox as we have never had this case before and we are working with Dwolla to locate your returned funds." The funds were finally returned on 3 May, nearly three months later, with a note: "Please be advised never to cancel any Dwolla withdrawals from us again".