Stablecoin issuer Tether has blacklisted a total of 39 Ethereum addresses that hold the USDT stablecoin.
Philippe Castonguay, an Ethereum researcher at Horizon Games, has created a dashboard on Dune Analytics, which shows that Tether had moved to ban the addresses beginning in November 2017.
Of the 39 addresses identified by Castonguay, 24 of those were blacklisted during 2020. A follow-up analysis of the addresses by The Block reveals that $5.51 million worth of USDT is being held in addresses blacklisted this year. The largest holding — $4.56 million — was blacklisted on April 5.
Blacklisting means that the addresses in question cannot send, receive or redeem USDT. In effect, the Tether tokens held in those addresses have been rendered unusable.
When reached for comment, Stuart Hoegner, general counsel at Bitfinex, a sister company of Tether, told The Block that Tether works with international law enforcement agencies and moves to block addresses when necessary.
"Tether routinely assists law enforcement in their investigations... Through the freeze address feature, Tether has been able to help users and exchanges to save and recover tens of millions of dollars stolen from them by hackers," said Hoegner.
Tether's development came to light after The Block first reported that CENTRE, which issues the USDC stablecoin, blacklisted an Ethereum address holding 100,000 USDC for the first time.
A CENTRE spokesperson said that the consortium, managed by Circle and Coinbase, blacklisted the address "in response to a request from law enforcement."