Five years of memorized handwritten notes is a bit more old school corporate/state espionage than remote network breach, https://nationalpost.com/news/exclusive-did-huawei-bring-dow...

  Security advisor Brian Shields discovered that not one, but seven Nortel executives, including CEO Frank Dunn, had been hacked, and that the hackers were vacuuming an alarming volume of sensitive material out of its databases. By the end of his investigation, Shields says he was able to track the theft of over 1,400 documents.. during a six-month period when bosses allowed him to monitor the stealing. He found evidence the break-in of Nortel’s internal computer network had started no later than 2000, and probably began in the 1990s. He says it lasted past 2009..

Reminds me of when those European monks smuggled silkworms out of China.