privacy in public places

Perry E. Metzger perry at
Fri Aug 29 10:05:39 EDT 2008

pgut001 at (Peter Gutmann) writes:
> "Perry E. Metzger" <perry at> writes:
>>Unfortunately, I don't see anything technological that people can reasonably
>>do here to provide more privacy, 
> Painting the camera lenses with laser pointers is quite effective, at least as
> a short-term civil-disobedience measure.  Since there's no long-term damage
> caused (unless you use a really impressive laser pointer) it's a bit tricky to
> charge you with anything, at least under current law.
> Or you could follow the lead of Captain Gatso in the UK...

There are now quite reasonable cameras about half a cm on a side. The
market is largely driven by cellphones. They were available in quantity
for under $10 a few years ago -- they are probably much cheaper by
now, and the prices are only going to come down further. There are of
course limits imposed by optics, but they aren't nearly so bad as is
often depicted, so with time we can expect the cameras to get better
and cheaper.

One can only laser or cut down a camera if one can find it. I could
probably saturate the average location with practically if not
literally undetectable cameras right now. It will continue to get
cheaper to do so with time.

Software already allows good 3D reconstruction of scenes based on
multiple images from different angles, and improvement of resolution
based on multiple images as well. The software will only get better
with time. Storage is, of course, only getting cheaper.

Autonomous vehicles, especially very small flying vehicles, already
exist and will improve with time. We already know from nature that it
is possible to construct quite small flying devices with high
resolution imaging and other sensors -- it will only be a matter of
time (perhaps a decade, a few decades at most) before artificial
"flies" can be built, and once they are built, it will only be a
matter of time before they cost very little. The images they produce
will be limited by optics, but again, they will not need to be as bad
as one naively expects, and we are getting better and better at
techniques for combining images to produce surprising results.

This arms race heavily favors the attacker over the defender.

I don't want to saturate this mailing list with a discussion of the
problem (I'm not going to pass many messages on it), but I think it is
a reasonable issue for people to contemplate. Perhaps I should allow a
more significant discussion in a month or two after people have
digested it for longer.

Perry E. Metzger		perry at

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