The HTC and Huawei Android phones were found to have software imbedded in hardware that was sending the contents of the Flash Drives to servers in China. That's why they were forbidden to be used for our government or military uses or sold in Military exchanges.
It was not that Blackberries were assembled in China that was the problem for use in Government, but that the Blackberry servers were located in Canada, not in the US. . . and that their encryption was bolted on, not intrinsic. Apple iPhone is built into the OS and the passcode is not even stored on the device.
Mark