The Department of Homeland Security appears to have shut down the ability to use Mt. Gox, a Bitcoin trading platform and mobile payment service.
It has managed this by refusing to complete the bank transfers to Mt. Gox. It appears that the Department of Homeland Security and US District Court for the District of Maryland issued a ‘Seizure Warrant’ for the funds associated with Mutum Sigillium’s Dwolla account (a.k.a. Mt. Gox).
Mt. Gox has admitted that its Dwolla transactions are not getting processed but it says that it has not been provided with a copy of the court order and/or warrant. It said that MtGox is investigating and will provide further reports when additional information becomes known.
Mt. Gox is one of the world's more established Bitcoin exchanges which trades bitcoins with other people around the world in their local currency.