Bitcoin Magazine U.S. Bitcoin Custody Concerns Rise After Alleged Insider Stole $40 Million In Digital Assets Allegations that an insider connected to a U.S. Marshals Service crypto contractor siphoned more than $40 million from government-linked wallets have raised fresh concerns over how the federal government safeguards seized bitcoin and other digital assets. U.S. Bitcoin Custody Concerns Rise After Alleged Insider Stole $40 Million In Digital Assets Micah Zimmerman.