Some of the bulletin board software like vBulleting need to practice better web usability. Today I was doing several searches and in each time I had to enter a captcha. I am not sure what the issue is. Do some sites have problems with bots doing automated searches that they have to place a captcha? Even if they have a valid reason, why can't they bring up a captcha the first time only instead of every single time? If the first attempt passes the verification, pass in a cookie with a value that I am a real human. It's simple.
This whole captcha is getting out of control. I am logged in into the site, isn't that proof that I am human? Or bring up a captcha only if the site detects an overwhelming search attempts from the same ip address during a set period of time. Don't just bring up a friction causing verification system automatically in the first search attempt and every one thereafter without trying to see if the search attempts are slowing down the system. If you're running a spiffy system which can handle thousands of searches, do you really need a captcha? Or are you trying to protect your site from scrapers?
Whatever your reason is, bring up a verification system only when you really have to.
You can read my other post about a non intrusive human verification system without using captchas.