I recall a story from many years ago - possibly an urban myth -
where some guy stuck a pin through a ham's coax feeder and thereby
took him off air/blew up his rig etc. Given that RF shorts are a
totally different kettle of fish from DC shorts, I'm just wondering
how feasible from a technical perspective this reported act of
sabotage is.
I'm no expert on transmission lines, but it strikes me that the
efficacy of such a stunt depends to a great extent on the point in the
line where the pin is inserted as related to the wavelength of the
transmitted signal. We all know short and open stubs are used as
matching elements at the higher frequencies, so it's implicit that
just sticking a pin in anywhere isn't necessarily going to adversely
affect the efficiency of an antenna system, unless one hits a node at
the frequency of operation. What I mean is, IOW, you won't
successfully short out coax at RF unless you stick the pin in at an
appropriate point. Of course, I might be full of crap on this one as
antennas have never been my strong point. Can anyone enlighten me?

btw: this is for academic discussion only! I've no beef against any
amateur and have been one myself for over 20 years.
--

"What is now proved was once only imagin'd" - William Blake