[galen211]

fwiw, Coinbase wouldn't be the first financial institution to challenge a John Doe Summons. The IRS issued one to UBS in 2008 (https://www.justice.gov/archive/tax/txdv08584.htm). UBS claimed it couldn't comply with the summons without breaking Swiss bank secrecy law, and the Dept of Justice ultimately came to an agreement directly with the Swiss government (under an existing tax treaty) to get the records it was seeking. Simultaneously, the IRS set up a voluntary disclosure program for Americans to pay a penalty on back taxes and avoid criminal prosecution. The amount of back taxes owed on bitcoin capital gains is probably less than the amount being sheltered by the Swiss in 2008, but it's not nothing.