Authentication Security Codes

Security code verifications have been commonplace for a half a decade now, perhaps longer. You have probably been forced to enter in a series of characters when registering for a new e-mail address, IM screen name, or for a promotion at virtually any website. Security codes essentially combat against automated junk registrations that can flood systems, exposing those within a community to unwanted junk e-mail or other solicitations. But take a look at these two examples:

What I have noticed lately is that these security codes are getting quite elaborate--and increasingly difficult to decipher. So many of them have these ridiculous looking artifacts in them and are stretched so badly that they are practically beyond recognition. I think I have about a 40% chance at getting it right the first time. And on some sites, if you get the security code wrong, it throws you out and forces you to enter in all of your information again.

I understand that this is a feature designed to prevent fraudulent registrations, but I figure that if a literate human being can't recognize the characters, then the system itself is flawed.