Not a bad idea. Maybe we could require captcha for the first 30 posts. With the new reCAPTCHA, most of the time, you won't have to solve a captcha anyway, since it uses heuristics to determine the likelihood that a given user is human.
The latest measures have dropped the amount of spam we see here by a huge amount. CAPTCHA isn't a bad idea, the question you need to ask is whether or not it's worth twicker's effort. If you're commenting about the lack of people moderating this site on Christmas then I don't know what to tell you besides "duuuhhh". Our current system works great at every other time of the year.
I am curious though, what is 'night' to you? This is an international forum with regular contributors from every corner of the planet.