https://yro.slashdot.org/story/16/11/18/2146221/irs-demands-identities-of-all-us-coinbase-traders-over-three-year-period
http://motherboard.vice.com/read/irs-demands-identities-of-all-coinbase-traders-over-two-year-period
https://www.documentcloud.org/documents/3222198-Petition-for-Coinbase-Trader-Identities.html
https://twitter.com/zerohedge/status/799401350824132608
https://www.documentcloud.org/documents/3222199-Memorandum-in-Support-of-Petition-for-Coinbase.html

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.