Since when did Yahoo change it so the minimum length for an answer is 15 characters?

It seems like they're updating a lot of things that include adding a captcha while posting questions and answers now
Update: Nevermind my question, just read it on a popular question just now.

But when did they come out with CAPTCHA and eliminate spammers?
Update 2: If that's the case, that's awesome since this site ever since 2013 went downhill with trolls and bots especially on the Yahoo Products category for some reason.
Update 3: Finally Yahoo is making a change for the better.
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