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 nose. 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.) A -- Andrew Sullivan Dyn, Inc. asullivan@dyn.com