In October, 2000, when Microsoft was presumably working on what would become XP, they were hacked. Somebody broke into their systems and managed to at least look at source code for Windows and Office. The folks in Redmond dutifully called in the FBI, examined their code and found it hadn’t been compromised. Or so they said.
“It is clear that hackers did see some of our source code,” Ballmer announced to a group of reporters and programmers at a seminar he was attending in Stockholm. “I can assure you that we know that there has been no compromise of the integrity of the source code, that it has not been modified or tampered with in any way.”