Suggestions for the future on your web site: (was cookies, and before that Re: Dreamhost hijacking my prefix...)

Andrew Sullivan asullivan at
Thu Jan 24 21:58:24 UTC 2013

On Thu, Jan 24, 2013 at 04:43:47PM -0500, Jean-Francois Mezei wrote:
> It is better to have a tent with holes in the screen door than no screen
> door. If the damaged screen door still prevents 90% of mosquitoes from
> getting in, it does let you chase down and kill those that do get in.

I get this argument, but it seems to miss the point I was trying to
make earlier.  This isn't like a screen door with holes in it, but
more like a screen door with holes in it and a trick hinge that, from
time to time, bounces back and whacks the humans entering right in the

To resort to plain language instead of overworked metaphor, the
problem with CAPTCHAs is that they're increasingly easier for
computers to solve than they are for humans.  This is perverse,
because the whole reason they were introduced was that they were
_hard_ for computers but _easy_ for humans.  The latter part was a key
design goal, and we are increasingly ditching it in favour of "just
using a CAPTCHA" because they're what we think works.

(Of course, this is really just a special case of the usual problems in
HCI when security becomes an issue.  We have this kind of problem with
passwords too.)


Andrew Sullivan
Dyn, Inc.
asullivan at

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