🚀 go-pugleaf

> ... it might result in one
> being chased and then charged with something nasty like
> obstruction of justice (anyone know if they can do this?).

Interfering with a police officer in the performance of his duties is
usually a serious offence.  Almost anything you do to interfere with a
police radar setup would probably qualify, if detected.

> How about a near infrared emitter which will fog the film
> but be invisible to the operators? ...

Might work.  Remember that "near infrared" is not entirely invisible if
it's bright; the eye's sensitivity tails off in the IR, but it doesn't
go immediately to zero.  Some of the near-IR fiber-optic wavelengths are
visible, dimly, in a dark room.  Your IR flash is going to have to be
pretty bright if it's going to mess up the picture seriously.  It might
be better to try for localized effects in crucial areas like the license
plate.  Near-IR markings, brightly lit in the near IR, might make it
impossible to read the number.  I don't know offhand whether suitable
marking materials are available, though.
-- 
Those who do not understand Unix are |  Henry Spencer @ U of Toronto Zoology
condemned to reinvent it, poorly.    | {allegra,ihnp4,decvax,utai}!utzoo!henry