Perry's Paint Fable comes to mind...

[Greg Broiles]

On Thu, Dec 14, 2000 at 03:50:55AM -0800, R. A. Hettinga wrote:
> Real-To:  "R. A. Hettinga" <rah at shipwright.com>
> 
> At 11:35 PM -0600 on 12/13/00, by way of believer at telepath.com wrote:
> 
> 
> > FOR ALL TO SEE
> > It's a spray which renders sealed envelopes transparent, making the
> > letters inside as easy to read as postcards. "It leaves an odour for 10
> > to 15 minutes," says the spray's inventor, but, apart from that, "no
> > evidence at all" that it's been used. While the manufacturer describes
> > "See-Through" as a "non-conductive, non-toxic, environmentally safe
> > liquid", human rights activists believe "it's an ethically questionable
> > product" which could tempt security forces to bend laws.
> > http://www.newscientist.com/news/news.jsp?id=ns226930

Inventor? Shit. 

You can achieve this result with the "canned air" dusters sold to 
computer techs and photo people by simply turning the can upside down
so the magic stuff emerges in liquid, not gaseous form - drip or spray
it on the envelope in question, and the paper becomes (partially)
translucent. 

The human rights activists are just pissed off they can't afford it
themselves if they order it from a spy catalog. Everyone can afford it
at Fry's - and learn thing about their friends and neighbors that they'll
someday wish they hadn't.

--
Greg Broiles gbroiles at netbox.com
PO Box 897
Oakland CA 94604