A popular Chinese social media app has been blocked in Russia because it didn’t provide the Russian communications watchdog with its contact details. WeChat, China’s most popular social media app, has been cut off since May 4, Russian authorities said in a statement. Tencent Holdings, which developed WeChat, told Reuters it was looking into the matter and was in touch with Russian authorities. Roskomnadzor, Russia’s communications watchdog, has taken similar measures against social networking sites in the past, having blocked LinkedIn last year for failing to transfer data on its Russian users to servers in Russia. While WeChat is not especially popular among Russians, Chinese tourists and businessmen in the country are not likely to be pleased with the measure.