tiger team [U.S. military jargon] n. 1. Originally, a team whose purpose is to penetrate security, and thus test security measures.
These people are paid professionals who do hacker-type tricks,
e.g., leave cardboard signs saying "bomb" in critical defense
installations, hand-lettered notes saying "Your codebooks have
been stolen" (they usually haven't been) inside safes, etc. After
a successful penetration, some high-ranking security type shows up
the next morning for a `security review' and finds the sign,
note, etc., and all hell breaks loose. Serious successes of tiger
teams sometimes lead to early retirement for base commanders and
security officers (see the patch entry for an example).
2. Recently, and more generally, any official inspection team or
special firefighting group called in to look at a problem.
A subset of tiger teams are professional crackers, testing the
security of military computer installations by attempting remote
attacks via networks or supposedly `secure' comm channels. Some of
their escapades, if declassified, would probably rank among the
greatest hacks of all times. The term has been adopted in
commercial computer-security circles in this more specific sense.