Original: Reuters / Mike Segar

JPMorgan Chase was slapped with a lawsuit Tuesday on behalf of a proposed nationwide class, accusing the financial institution of charging surprise fees when it stopped letting customers buy cryptocurrency with credit cards in late January and began treating the purchases as cash advances.

The named plaintiff in the lawsuit is Brady Tucker, an Idaho resident who was charged $143.30 in fees and $20.61 in surprise interest charges for five Coinbase transactions between January 27 and February 2. In addition to Tucker, there are hundreds to thousands of other Chase customers who were hit with similar charges, claims the lawsuit.

Chase spokeswoman Mary Jane Rogers declined to comment on the lawsuit. However, she did note that the bank halted credit card purchases for cryptocurrency on February 3rd, due to the credit risk involved with the highly volatile asset class. The credit card ban decision was made in solidarity with other major financial institutions, including Bank Of America, Citigroup, Capital One and Discover.

The lawsuit accuses Chase of violating the U.S. Truth in Lending Act, which requires credit card issuers to notify customers in writing of any significant change in charges or terms, and is asking for actual damages and statutory damages of $1 million.