CAPTCHA is necessary for the same reason locking your car/house is necessary. You can probably not do it 9 times out of 10 and it will be fine, but then that 1/10 happens, all your stuff gets stolen, and you start locking your doors 100% of the time.
Anyway, at one point we decided to just block the IP ranges from countries like Russia and Vietnam, which seemed to have the most spam accounts.
I think I made my account around 3 years later.
Of course most people aren't spammers or burglars so in most cases it doesn't matter.
On the third hand, I understand US schools have metal detectors these days, and in Beijing I had to go through a metal detector to hop on the metro, so what do I know...
Well, a more apt one would be that someone breaks into your house or car and puts all their litter everywhere so that you have to spend hours or days cleaning.
Sometimes I don't get the logic of these spambot creators. Do they honestly believe that creating thousands of fake accounts with links to "hot dating site" in my webshop will help them in any way? These data are completely invisible outside (why would anyone want to present their customer data to the world).
wow, this actually happened to a coworker. He waked up one day discovering a broken window and human excrement everywhere.
For sure he closes everything now.
The goal is link building[1].
I don't think they actually expect the links to be published, so much as they expect the webmaster to read them in their moderation panel.
Eventually they even added it. Spam and vandalism was just too bad.
These are much better for the users, you share less data with Google and others, and are fairly trivial to implement. Easy to circumvent, but spammers aren't looking at you specifically.
Option A: 10% of time their unlocked house is broken into.
Option B: The poster was using an analogy to illustrate a point.