Technically, it's not a formal entry. Heck, it's not even "legit", but Xiaomi fans in the US will probably take what they can. The Chinese superstar OEM has, for a long time, signified its desire to enter the US smartphone market but hasn't made any concrete steps to do so. Sensing a business opportunity, carrier US Mobile, which uses T-Mobile's network, has just added a couple of Xiaomi's, as well as Meizu's, smartphones to its shelves. But in a blink of an eye, they were gone, probably because of their shady nature.