For about $50, you can get a smartphone with a high-definition display, fast data service and, according to security contractors, a secret feature: a backdoor that sends all your text messages to China every 72 hours.Security contractors recently discovered preinstalled software in some Android phones that monitors where users go, whom they talk to and what they write in text messages. The American authorities say it is not clear whether this represents secretive data mining for advertising purposes or a Chinese government effort to collect intelligence.
http://www.nytimes.com/2016/11/16/us/politics/china-phones-software-security.html