The breach is said to be limited to unclassified emails but the inboxes of Burns and Kritenbrink reportedly could have exposed details of US administration's planned trips to China and details of its policy towards China.
Other applications from the same website include 'How and when will you die?', 'love calculator', 'Twitter circle' (another famous app), 'Who visited your Twitter profile?' (it was once quite famous on Twitter), 'Twitter Crush' and more.
Last month, in three separate cases, the US government charged 13 individuals, including members of China's security and intelligence apparatus and their agents, for alleged efforts to unlawfully exert influence in the United States for the benefit of their government.