Tsutomu Shimomura has been variously described as a security
maven, security
expert,
NSA spook, Caltech
hacker.
He was responsible for tracing Kevin Mitnick after the latter broke into his computer using IP spoofing and copied his cellphone hacking tools and source.
Of course there was a legitimate reason Shimomura had this stuff in the first place (You might want to ask John Markoff exactly what it was).
Can anyone say disable rlogin?