Stabelcoin issuer Tether froze 41 wallets controlled by people on the Office of Foreign Assets Control's (OFAC) Specially Designated Nationals (SDN) List on Saturday.
Tether described the actions as "precautionary measures" in a blog post.
On-chain data shows that several wallets had been using coin-mixing service Tornado Cash in the past six months. One of the frozen wallets is also associated with the $625 million Ronin Bridge attack, which, according to the U.S. Treasury Department, was executed by North Korean hacking group Lazarus Group.
"By executing voluntary wallet address freezing of new additions to the SDN List and freezing previously added addresses, we will be able to further strengthen the positive usage of stablecoin technology and promote a safer stablecoin ecosystem for all users," said Tether CEO Paolo Ardoino.
In October, Tether froze 32 wallets that were linked to terrorism and warfare in Ukraine and Israel. It also froze $225 million last month in relation to a human trafficking syndicate following an investigation by the U.S. Department of Justice.