An anonymous reader quotes a report from Motherboard: In bitcoin-related investigations, authorities will often follow the digital trail of an illegal transaction or suspicious user back to a specific account at a bitcoin trading company. From here, investigators will likely subpoena the company for records about that particular user, so they can then properly identify the person suspected of a crime. The Internal Revenue Service, however, has taken a different approach. Instead of asking for data relating to specific individuals suspected of a crime, it has demanded bitcoin trading site Coinbase to provide the identities of all of the firm's U.S. customers who made transactions over a three year period, because there is a chance they are avoiding paying taxes on their bitcoin reserves. Coinbase has a total of millions of customers. According to court filings, which were first flagged by financial blogger Zerohedge on Twitter, the IRS has launched an investigation to determine the correct amount of tax that those who use virtual currencies such as bitcoin are obligated to pay. But according to the documents, the IRS is asking for the identities of any U.S. Coinbase customer who transferred crypto-currency with the service between 2013 and 2015. "The John Does whose identities are sought by the summons are United States persons who, at any time during the period January 1, 2013, through December 31, 2015, conducted transactions in a convertible virtual currency," reads a memorandum written by Department of Justice attorneys and filed on Thursday, November 17.