http://technolog.msnbc.msn.com/_news...-than-a-decade

The Wall Street Journal has found that, for more than a decade, hackers appeared to have unfettered access to Nortel Networks' corporate computer system, downloading potentially sensitive information found in "technical papers, research-and-development reports, business plans, employee emails and other documents."...
Pretty crazy, also the article notes later that:

...infection through former employees who still have Nortel equipment may very well have contaminated other networks, especially as the company has broken up in various stages over the years.