Where's the Forum Bugs and Feedback Sticky? We need one.
And it can start with this: Get rid of these ****ed "captchas."
As others have noted, I've got to be signed in to post. And, in several months of being fairly active on this forum, I haven't seen a single instance of robo-posting.
If I just want to post one reply to someone and don't plan to stay on here all day, the fact that I've only got to do the captcha once actually means I have to fill it in for every single post. Which is something I'm not willing to do. Not saying I'll boycott or quit this forum if they don't get rid of the captchas but I'm already spending far less time here than I used to and this could easily be the sort of thing that keeps me from coming here at all. It'll certainly cut down on my willingness to post anything.
Get rid of it. We don't need it here.
Captchas for every post is definitely overkill. Having users with a low post count or a fresh registration date would be more effective since spammer accounts are going to be new accounts with relatively low post counts by the time they are found and purged.