[crooked-v]

One of the Discworld novels uses 'hacking' of multi-shutter semaphore towers as a plot point, by way of a gibberish sequence that can physically destroy the poorly engineered towers by slamming the shutters around at a resonant frequency (book) or cause the controls to physically seize up in a jammed position (film).

[smallnamespace]

Real physical layers are quite vulnerable to this type of disruption and we actually mitigate this by paying rather high costs at the bit encoding level:

https://en.wikipedia.org/wiki/8b/10b_encoding

https://en.wikipedia.org/wiki/64b/66b_encoding

https://en.wikipedia.org/wiki/Scrambler

[sophacles]

GNU Terry Pratchett

http://www.gnuterrypratchett.com/