A press release from the US Senate Armed Services Committee has revealed that hackers believed to be connected with the Chinese government successfully broke into the computer systems of airlines and military contractors more than 20 times in one year.  The systems penetrated concerned arrangements for the global movement of US troops and equipment.  In a one year period, the hackers made 50 hacking attempts with 20 attempts being successful.

United States Senate Committee on Armed Services press release – 17 September 2014