The document went on to illustrate a complex military cyber-espionage unit based in Shanghai, that had been busy scouring the networks of more than 140 companies.

While accusations continue to fly and denials resound, there are now some who believe China may actually have meant to be caught.

“They're very careful not to cover their tracks very well,” Yael Shahar, an Israeli cybersecurity expert at the International Institute for Counter-Terrorism, told the National Journal. “It's a projection of power; it's not that they're trying to hide it,” adding that it enhanced Chinese self-perceptions of “face” to leave a calling card.

In other words, the Chinese hackers may have wanted to be exposed as a public demonstration to Washington of Beijing's level of skill and infiltration.