In addition to showing off the world's first phone with a camera under the screen at MWC 2019 Shanghai, Oppo unveiled an unexpected smartphone feature, especially for a smartphone maker from China. It's called MeshTalk, and as the name hints, it lets you connect to other phones around you. There's no need for Wi-Fi, Bluetooth, or cellular service to get the job done, and it works over distances of up to 3km (1.86 miles).The nifty new technology could help you communicate with others in all sorts of instances where regular service isn't available. MeshTalk isn't a new concept, as chat apps exist that deliver the same type of chat experience. There are even devices that let you talk and text on any smartphone without Wi-Fi or a cellular connection. However, Oppo's app will be built right into its Android devices, which means you'd have access to mesh communication right out of the box -- and that includes text, voice messages, and regular voice calls."At times, we encounter extreme situations when there is no network coverage at all -- for example, when you just arrive at an airport in a foreign country or when you take an off-road trip or attend a concert, football match, or exhibition," Oppo said in a press release (via VentureBeat). "[This] technology offers a solution to such scenarios in which other network connections are unavailable."MeshTalk could be useful during natural disasters or to connect people living in remote places, sure. But you might also want to use this particular type of technology is when an oppressive regime turns off access to the internet during episodes of public unrest. Or where a government tries to forcefully shut down an encrypted app that's used by demonstrators -- it happened in Hong Kong with Telegram just last week.And that's why it's surprising to see a Chinese smartphone maker unveil this particular type of chat app, which might not be in the best interest of the Chinese government. That said, it's unclear how secure this MeshTalk app is compared to end-to-end encrypted services that require internet access, like Telegram, or how well it protects the user's privacy.