has nothing to do with Russia, according to the linked article

Pourquoi était-il sous la menace d'un mandat de recherche ?

La Justice considère que l’absence de modération, de coopération avec les forces de l’ordre et les outils proposés par Telegram (numéro jetable, cryptomonnaies…) le rend complice de trafic de stupéfiants, d’infractions pédocriminels et d’escroquerie.

Ce mandat de recherche courait si, et seulement si, Pavel Durov se trouvait sur le territoire national.

En effet, Telegram est une ruche pour les contenus criminels. En ce moment, la plateforme fait l'actualité avec la diffusion illégale des matchs de Ligue 1. Mais sur cette messagerie chiffrée, de nombreux comptes sont utilisés par la criminalité organisée. Au-delà du terrorisme, les plus dangereux pédocriminels communiquent sur Telegram pour échanger des contenus. "C'est devenu depuis des années LA plateforme numéro 1 pour le crime organisé", commente un enquêteur.

even if it's not about telegram, this might help to understand ☞ https://www.laquadrature.net/en/2023/12/15/encryption-discussion-during-the-8-december-trial-from-myth-to-reality/

Several of the defendants were questioned about their use of tools and software such as Signal, Tor and Tails, and about the encryption of their computers and hard drives. The questioning followed the same pattern as the prosecution’s investigations, which we revealed a few months ago: a huge amount of confusion as to the technical understanding of these tools combined with a suspicious approach to their actual use. Three defendants were questioned about their motivation for using such software, as if a well-argued justification was needed, even though the tools are perfectly normal, legal and ordinary.

“It is possible and not forbidden to have these tools, but we can ask ourselves why dissimulate information” the president of the court stated. Suspicion of clandestinity coupled with little knowledge of the subject was evident in their questions: “You explain that the use of this ‘kind of network’ [Signal] was to preserve your privacy, but are you afraid of being monitored?”. Or: “Why did you think it was important or a good idea to find out about this ‘kind of environment’ [the Tails operating system]?”.