Hey there,
I found for myself that these Captchas are sometimes really really unreadible and moreover they don't work sometimes, like you type exactly what is there and it just won't work. It's really annoying and I think alot people will be stopped from writing down in these forums(myself also from time to time )
also to mention is that there's no way to get a new captcha if the one's before is not working, like you try it several times and it just won't work - only way is to create the post again from complete new... not the comfortable way