Share this article
IRS Sued by Ex-Coinbase User Over Seizure of Financial Records
Jim Harper claims the tax collector violated his Fourth Amendment rights by seizing his crypto account records without obtaining a warrant.
By Danny Nelson
Updated Sep 14, 2021, 9:31 a.m. Published Jul 15, 2020, 4:00 p.m.

A former Coinbase user who last August received the now-infamous Internal Revenue Service (IRS) crypto letter is suing to block the tax agency from unlawfully seizing private financial records.
Don't miss another story.Subscribe to the Crypto Daybook Americas Newsletter today. See all newsletters
- Bitcoin researcher Jim Harper accused the IRS, its commissioner and up to 10 unnamed agents of violating his privacy and due process rights under the Fourth and Fifth Amendments of the U.S. Constitution in a 26-page civil action filed in New Hampshire District Court on Wednesday.
- Last summer, Harper and more than 10,000 other taxpayers learned in a “soft letter” that the IRS had “information” on their cryptocurrency accounts. IRS agents wrote they had reason to believe he had not paid taxes on the crypto. (Harper claims he’s paid his crypto taxes in full since 2013.)
- The IRS never said where it got its “information,” but Harper believes his details may have been among the trove of 13,000 account records that IRS agents seized from Coinbase in early 2018 following a court order and controversial legal fight.
- “If they acquired it via the Coinbase summons – and we don't know that for sure – it was a defective process that denied me the opportunity to contest the seizure of my data,” Harper told CoinDesk in an email. “I'll be seeking destruction of the records in the IRS's control. A win would allow all recipients of the letter to seek the same.”
- Caleb Kruckenberg, a New Civil Liberties Alliance lawyer who is representing Harper pro bono, told CoinDesk Harper’s case is an opportunity to put some checks on the power of the administrative state.
Read the full filing below:
More For You
Protocol Research: GoPlus Security

What to know:
- As of October 2025, GoPlus has generated $4.7M in total revenue across its product lines. The GoPlus App is the primary revenue driver, contributing $2.5M (approx. 53%), followed by the SafeToken Protocol at $1.7M.
- GoPlus Intelligence's Token Security API averaged 717 million monthly calls year-to-date in 2025 , with a peak of nearly 1 billion calls in February 2025. Total blockchain-level requests, including transaction simulations, averaged an additional 350 million per month.
- Since its January 2025 launch , the $GPS token has registered over $5B in total spot volume and $10B in derivatives volume in 2025. Monthly spot volume peaked in March 2025 at over $1.1B , while derivatives volume peaked the same month at over $4B.
More For You
Crypto exchange HashKey's shares fall 5% on trading debut in Hong Kong

Investors questioned whether Hong Kong’s dominant licensed exchange can turn surging volumes and regulatory advantage into sustainable profits.
What to know:
- HashKey Holdings' shares fell about 5% in their Hong Kong trading debut, highlighting investor caution despite the company's dominant market position.
- The company reported significant losses due to its ultra-low fee strategy, which has not kept pace with operating costs.
- HashKey's growth is increasingly tied to Hong Kong's regulatory framework, affecting its market outlook.
Top Stories











