Pavel Durov, Telegram founder and former CEO of Vkontakte, in happier (and younger) days.

Late this afternoon at a Parisian airport, French authorities detained Pavel Durov, the founder of the Telegram messaging/publication service. They are allegedly planning to hit him tomorrow with serious charges related to abetting terrorism, fraud, money laundering, and crimes against children, all of it apparently stemming from a near-total lack of moderation on Telegram. According to French authorities, thanks to its encryption and support for crypto, Telegram has become the new top tool for organized crime.

The French outlet TF1 had the news first from sources within the investigation. (Reuters and CNN have since run stories as well.) Their source said, “Pavel Durov will definitely end up in pretrial detention. On his platform, he allowed an incalculable number of offenses and crimes to be committed, which he does nothing to moderate nor does he cooperate.”

Durov is a 39-year-old who gained a fortune by building VKontakte, a Russian version of Facebook, before being forced out of his company by the Kremlin. He left Russia and went on to start Telegram, which became widely popular, especially in Europe. He was arrested today when his private plane flew from Azerbaijan to Paris’s Bourget Airport.

Telegram has become a crucial news outlet for Russians, as it is one of the few uncensored ways to hear non-Kremlin propaganda from within Russia. It has also become the top outlet for nationalistic Russian “milbloggers” writing about the Ukraine war. Durov’s arrest has already led to outright panic among many of them, in part due to secrets it might reveal—but also because it is commonly used by Russian forces to communicate.

As Rob Lee, a senior fellow at the Foreign Policy Research Institute, noted tonight, “A popular Russian channel says that Telegram is also used by Russian forces to communicate, and that if Western intelligence services gain access to it, they could obtain sensitive information about the Russian military.”

Right wing and crypto influencers are likewise angry over the arrest, writing things like, “This is a serious attack on freedom. Today, they target an app that promotes liberty tomorrow, they will go after DeFi. If you claim to support crypto, you must show your support #FreeDurov it’s time for digital resistance.”

Durov appears to be an old-school cyber-libertarian who believes in privacy and encryption. His arrest will certainly resonate in America, which has seen a similar debate over how much online services should cooperate with law enforcement. The FBI, for instance, has occasionally warned that end-to-end encryption will result in a “going dark” problem in which crime simply disappears from their view, and the US has seen repeated attempts to legislate backdoors into encryption systems. Those have all been defeated, however, and civil liberties advocates and techies generally note that creating backdoors makes such systems fundamentally insecure. The global debate over crime, encryption, civil liberties, and messaging apps is sure to heat up with Durov’s arrest.

By Holden