TikTok called the decision "regrettable".
Paris, France:
France has taken the dramatic step of blocking TikTok in its Pacific territory of New Caledonia, as part of efforts to quell days of violent unrest.
It is the latest clash between democratic governments and the Chinese-owned social media platform.
Using "state of emergency" powers, users of New Caledonia's sole telecoms operator have been unable to access the hyper-popular app since Wednesday.
Why was it banned?
Critics have long accused TikTok of platforming misinformation, harvesting sensitive data, fuelling social unrest -- particularly in countries at odds with China -- and suppressing criticism of Beijing.
Scores of European countries have barred their public officials from using the app for national security reasons. The United States is considering an outright ban unless ownership changes are made.
But France's decision appeared more practical: The government believes the app was being used by those opposed to French rule to communicate and organise violent protests.
Can they do that?
Nicolas Hervieu, a legal expert at Paris's Sciences-Po university, said the decision was "without precedent" and may not hold up to legal scrutiny.
According to Amelie Tripet, a media lawyer with the August Debouzy firm, the decision was made under rules dating back to 1955 that govern any state of emergency.
The law says that France's minister of the interior can block any communications service involved in planning or advocating "terrorism".
But according to Tripet, to justify such an "exceptional measure" it would have to be limited in duration and well justified.
"If this were ever challenged before a judge, there would be three questions: Was it permitted under the law? Was it necessary? Was it proportionate?" she said.
"It is potentially a legally fragile decision," she said.
How was it done?
The ban was carried out by New Caledonia's state-run Postal and Telecommunication Service -- a move made easier by the territory having only one mobile phone operator.
The most likely technical method, according to Adrien Merveille, a cybersecurity expert at Check Point Software Technologies, would be to block part of the system commonly referred to as the internet's phonebook.
The Domain Name System allows users to use word-based web addresses to flit between sites, rather than remembering Internet Protocol addresses that are made up of long strings of numbers.
"The way of stopping access to TikTok would simply be to say that requests made to TikTok do not generate a response. This is something that can be put in place at the operator level," he said.
What was the impact?
After four nights of serious unrest that have left shops disemboweled, streets littered with burned-out vehicles and five people dead, the violence appears to have eased.
Authorities reported the situation was "calmer and more peaceful" on Friday, but what role the ban played is impossible to say.
But some have doubts about the impact.
According to one VPN provider, the number of New Caledonians signing up to use virtual private networks that mask their location has risen 150 percent.
"State blocking has been practised in China and the Middle East for decades and it works" said Arnaud Lemaire an expert from cybersecurity firm F5.
"But it has limits, it can be circumvented with a VPN, bouncing through another country".
What happens now?
How long the ban lasts is likely to depend on tensions on the ground.
TikTok called the decision "regrettable" and said it was taken without "any request from the local authorities or the French government to take down content."
"Our security teams are monitoring the situation very carefully and ensuring that our platform is safe," a company official said. "We remain open to discussions with the authorities."
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)