In this case, where I was privileged to see these real examples, I suspect that the CAPTCHA itself was only marginally involved, as the cause of the problem being discussed, in Blogger Help Forum: Something Is Broken.
In looking at these three examples, I immediately hit "Publish" on the first two.
I attempted the third, simply because I wanted to move forward with the actual problem diagnosis.
The "easy" "words" which contain "characters" in black, on a clean white background, are sort of guessable. I've seen enough of them. They suck - but they are predictable.
The other "words", in the shadow box, with noisy details - I guess represent the latest attempt to keep them from being guessable by automated processes. These, I fear, are simply over the edge.
??? After looking several times, I can see a dim "3" - so I suppose I would guess that, if I was reasonably sure that I had a good chance with the other, relatively easy "word" ("tokshous"?).
????? This one, I cannot begin to see characters. I would immediately pass on this one, every time. Even if "asuchSe" is correct for the "easy" "word" (or might that be "asuch5e"??). FAIL.
I can sort of see characters - possibly all capital letters, and a space in the middle. A guess, fortunately correct, was "AF9" (hoping that the space was not significant). And, hoping "Iflages" to be the "easy" word (that could be "If1ages", just as easily).
You get one chance with each CAPTCHA - a wrong guess, on either "word", simply leaves you looking at a different CAPTCHA. So, you have no opportunity to learn from your mistakes.
The above 3 examples show the "non easy" "word" semi visible, at least. Recently, I have seen some CAPTCHAs where the "non easy" "word" was just a black box on the screen - no content at all visible. In one case, I hit "Publish" 4 times without entering anything - simply because I could see absolutely no detail in the black box. Will your readers be that persistent?
If you are using CAPTCHA screening in the comments, on your blog, you will have to decide for yourself whether you wish to continue doing so. I removed the CAPTCHA from my blog, a month ago. Had I not removed the CAPTCHA a month ago, I would most surely have done so, today.
Were I be idly preparing to comment on your blog (for any purpose not involving me diagnosing a problem for someone), and were I to encounter these CAPTCHAs, this would simply be the last time I attempted to publish a comment, on your blog.
Comment publication I regard as maybe optional - it's no great problem (to me) if I can't publish a comment, on your blog. I have no idea what I will do, when encountering these abominations under a high stress situation, however.
- Account creation.
- Account / blog unlock.
- Two step authentication necessitated re login (which I do see, regularly, when using the forums).
None of those 3 scenarios lend themselves to sitting there and guessing indecipherable puzzles, with marginally predictable outcome. Especially as my suspicion is that CAPTCHAs protect us only from the very simple hackers and spammers.
I don't force CAPTCHA screening, with commenting on this blog - though I will moderate.