The founder of encrypted messaging service Telegram has been detained in France over the weekend as part of an investigation into a lack of moderation and criminal use of the platform.
Authorities took Russian-born Pavel Durov into custody at Paris–Le Bourget Airport on Saturday evening, local time, immediately after his arrival from Azerbaijan on a private jet.
French prosecutors have declined to comment on the case but it was already known he had an arrest warrant in his name in France.
He was reportedly captured after authorities spotted his name on the airport's passenger list.
Mr Durov's arrest has drawn the ire of Russia, with Moscow claiming it highlights the West's double standard on freedom of speech.
Here's what to know about Telegram and its 39-year-old CEO and founder.
What is Telegram?
Now based in Dubai, Telegram was founded by Mr Durov and his brother in Russia in 2013 in the wake of the Russian government's crackdown on the internet after mass pro-democracy protests rocked Moscow.
The app uses end-to-end encryption which sees messages coded in a way where no-one but the sender and recipient can view them.
Telegram itself cannot monitor encrypted private communications, but it does have the ability to ban both channels and accounts.
The service currently has 900 million active monthly users and has positioned itself as a more secure alternative to US-owned platforms including WhatsApp and Signal.
It is particularly influential in Russia, Ukraine and the republics of the former Soviet Union, and has become a critical source of information on Russia's war in Ukraine, used heavily by government officials on both sides.
Mr Durov founded the platform after his first social media platform, VK, stirred up dispute with the Kremlin, forcing him to sell it off and leave Russia in 2014.
Having relocated himself to the United Arab Emirates (UAE) in 2017, Telegram shielded itself from moderation laws at a time when Western countries were pressuring large platforms to remove illegal content. Mr Durov praised the country for its "neutrality".
Telegram has become hugely popular partly due to the ease of viewing and posting videos on its messaging "channels", but critics accuse it of hosting often illegal content ranging from extreme sexual imagery, disinformation, and services for buying drugs, veiled behind a pro-privacy rhetoric.
Research has shown the app hosts thousands of far-right and extremist groups, and helps in the flow of their transnational communications, including that of Islamic State (IS).
But Steven Feldstein, a senior fellow at the Carnegie Endowment for International Peace, says Telegram "occupies a complicated position in the ecosystem", with both upsides and downsides.
"It is a place where known terrorist groups such as the Islamic State, and others, have used it to communicate propaganda to their followers," he told ABC News Channel.
"It's also a platform that can be used by different extremist groups, by criminal organisations to either pedal and propagate illicit activity, or to spread harmful messages.
"On the flip side, Telegram occupies a pretty important niche when it comes to allowing for criticism against authoritarian regimes, when it comes to being a place where you have unlikely conversations occurring."
Mr Feldstein said particularly with the war in Ukraine, Telegram had played a vital role in the free flow of information and presenting otherwise unheard-of viewpoints.
Ukrainian President Volodymyr Zelenskyy and his officials, as well as Vladimir Putin's government regularly use it.
Why was Pavel Durov arrested?
The investigation by France's OFMIN, an office tasked with preventing violence against minors, relates to allegations including fraud, sexual exploitation, drug trafficking, cyberbullying, organised crime and promotion of terrorism on Telegram, local media reported.
Mr Durov has been accused of allowing criminal activities to go on undeterred on the app, allegations the platform dismissed as "absurd".
"Telegram abides by EU laws, including the Digital Services Act — its moderation is within industry standards and constantly improving," the company said in a statement.
"Telegram's CEO Pavel Durov has nothing to hide and travels frequently in Europe … it is absurd to claim that a platform or its owner are responsible for abuse of that platform."
A French police source told Reuters the investigation also relates to Mr Durov's refusal to cooperate with authorities.
His current period of detention for questioning can last up to a maximum of 96 hours — until Wednesday night, local time. When this ends, the judge can decide to free him or press charges and remand in further custody.
Mr Durov holds citizenship of France, the UAE, Russia, and Saint Kitts and Nevis.
What is Russia's response?
Russia's embassy to Paris said it had demanded access to Mr Durov but had had no response, accusing France of "refusing to cooperate".
Russian foreign ministry spokeswoman Maria Zakharova said Moscow was taking steps to "clarify" the situation, but questioned whether Western NGOs would demand his release.
"In 2018, a group of 26 NGOs, including Human Rights Watch, Amnesty International, Freedom House, Reporters Without Borders, the Committee to Protect Journalists, and others, condemned the Russian court's decision to block Telegram," she said in a post on her personal Telegram account.
"Do you think this time they'll appeal to Paris and demand Durov's release?"
Billionaire owner of social media platform X, Elon Musk also came to the defence of Mr Durov, claiming his arrest was illustrative of an attack on free speech in Europe.
"It's 2030 in Europe and you're being executed for liking a meme," he said on X.
US whistleblower Edward Snowden, who took asylum in Russia, blasted "an assault on the basic human rights of speech and association", saying he was saddened Paris had "descended to the level of taking hostages as a means for gaining access to private communications".
While French authorities are yet to detail the facts of Mr Durov's case, his arrest is unusual for a dispute like social media content moderation, which is typically treated as a civil — not criminal — proceeding.
No charges have been laid against him so far.
ABC/wires
