The charges against Pavol Durov, CEO of Telegram. The French government has issued a press release detailing the specific changes against Pavel Durov, who was arrested Saturday, August 24 in Paris.
Besides the charges of not deleting salacious content, which I assume you have probably already heard about, the charges list things like: "Providing cryptology services aiming to ensure confidentiality without certified declaration," "Providing a cryptology tool not solely ensuring authentication or integrity monitoring without prior declaration," and "Importing a cryptology tool ensuring authentication or integrity monitoring without prior declaration."
Apparently in French law, there is a pre-declaration and pre-certification process software developers have to go through with the government. Pavel Durov has dual French and Russian citizenship. So I guess the French government figures their laws apply to him.
(Link goes to a PDF document. Pages 1 and 2 are in French and pages 3 and 4 have the same press release in English.)