WASHINGTON, Dec 16 (Reuters) - The U.S. Treasury Department on Thursday added eight Chinese technology firms, including drone maker DJI Technology Co Ltd, to an investment blacklist, according to the department"s website. Treasury"s move, which also added Megvii Technology Limited, Xiamen Meiya Pico Information Co Ltd and others to the list of "Chinese military-industrial complex companies," bars Americans from purchasing or selling certain publicly traded securities of the companies.