Telegram has blocked two major black markets—Xinbi Guarantee and Huione Guarantee—from operating on it platform, shutting down a significant source of criminal activity.

Xinbi Guarantee and Huione Guarantee are two markets that are popular options for cybercriminals and scammers, according to Reuters. As of Thursday, both appeared to be inactive. The move is a significant blow to online criminal activities, with research firm Elliptic estimating the two markets accounted for $35 billion in activity since 2021, putting them in the upper echelons of online black markets.

“This is a big blow for online fraudsters, who relied on these markets for stolen data, money laundering services and telecoms infrastructure,” Elliptic said in a statement, via Reuters.

Telegram’s Changing Stance

Telegram’s decision to block the two markets appears to be a noticeable departure from its previous pattern. The company has famously refused to cooperate with law enforcement in the past, but that stance landed founder Pavel Durov in legal trouble in France.

In the aftermath of Durov’s arrest, Telegram pledged to do more to cooperate with government efforts to combat illegal content. The company also joined the Internet Watch Foundation in an effort to combat CSAM.

Telegram was always in a unique position among secure messaging platforms, in that it did not enable end-to-end encryption (E2EE) by default, like Signal or WhatsApp do, instead leaving it up to users to enable E2EE for individual conversations.

As a result, unlike its rivals, Telegram could not claim that it had no knowledge of what people were doing on its platform and not ability to stop them or turn them over to authorities. That inherit culpability is what opened the door for Durov to be arrested.

It appears Telegram is making good on its promise to do more to regulate illegal content on its platform, with the shutdown of Xinbi Guarantee and Huione Guarantee likely only the beginning.