Here's my security story:
This happened about two years ago when I was
moving from the DC area(living about 10 mins
from IAD @ the time) to San Francisco.

I had family comp. tickets from IAD->SFO
on AA courtesy of an aunt who worked @ SABRE
as a programmer at the time.
I was flying out and shipping my stuff,
including the computers. With most computer systems you have to unship the hard drives and transport them seperately in a shock-proof hardcase of some sort. Since I
was planning on making a living off the data
on these particularc drive, it was very
important that they arrive in good condition,
so I packed them in the case very carefully
and was planning to carry them on. I requested a hand-inspect, not wanting to
trust them to the sways and vagaries of the
X-ray system. That was fine until they asked
me to turn them on. I couldn't of course because these were simply the drives themselves and need a power supply and cable
in order to actually work. Alone and by themselves, they are basically heavy black
bricks with a circuit board attached to them.
I tried to explain this to them. They didn't
understand and we went around on this a few
times. Finally an AA gate agent came over,
spoke w/ the head security guard on duty and
simply scribbled into a little ledger and
I was through. They didn't demand to Xray
them, I didn't get a free trip to the body-cavity-search room and I was on my way.

I didn't ask anybody what was going on, I
can only assume that she was signing some
sort of waiver of responsibility, more or
less putting it on her head if the plane
blew up because of me.