I'm reminded of the following description of the electronic thumb from Doulgas Adams' The Hitchhikers' Guide to the Galaxy[0]:
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> *Electronic Thumb*
> A short squat black rod, smooth and matte with a couple of flat switches and dials at one end. It allows Hitchhikers to flag down passing spacecraft to hitch a lift.
> The Thumb is used by Hitchhikers throughout the Galaxy to steal a ride aboard starships who's operators have little interest in taking along extra passengers.
> Half the electronic engineers in the galaxy are constantly trying to find fresh ways of jamming the signals generated by the Thumb, while the other half are constantly trying to find fresh ways of jamming the jamming signals.
---
> *Electronic Thumb*
> A short squat black rod, smooth and matte with a couple of flat switches and dials at one end. It allows Hitchhikers to flag down passing spacecraft to hitch a lift.
> The Thumb is used by Hitchhikers throughout the Galaxy to steal a ride aboard starships who's operators have little interest in taking along extra passengers.
> Half the electronic engineers in the galaxy are constantly trying to find fresh ways of jamming the signals generated by the Thumb, while the other half are constantly trying to find fresh ways of jamming the jamming signals.
[0]: https://sites.google.com/site/h2g2theguide/Index/e/339375