I've noticed that lately, whenever I have time to read through larger number of reviews to plan for a hobbying trip the captcha service kicks in often. If it's 1-3 captchas that's totally fine but this morning I had to deal with 16 captchas TWICE!  

I can't ever remember it happening more than 3 or 4 times and 90% of the time it's just the once. Could it be a browser issue on your end maybe?

After viewing x number of reviews the captcha will kick in. The whole captcha is via a third party captcha which will take in account your ip address.

AFAIK, if you answer a CAPTCHA incorrectly, it doesn't tell you but just presents another CAPTCHA. Is there a chance your answers were not what the CAPTCHA expected?

You beat me to it!  
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But I was going to add that some of the "answers" are never really clear to me. I'm talking about the 4 x 4 grids with photos, not the blurry alphanumerics. "Select all squares with motorcycles" or bicycles or chimneys or stairs or traffic lights or ... whatevers.  
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OK. But what if there is just a smidge of a motorcycle (handlebar tip; tiny piece of a tire; and is the RIDER a part of the motorcycle or not?) in the box? Is that a Y or N (plus or minus). Same thing about bicycles, cars, chimneys, stairs [does the side face of a stair count or only the step and riser?], ...)  Are you supposed to click on a smidge? For example, in the attached image, there are traffic lights in the top row:
-  + + +
-  -  -  -
-  -  -  -
-  -  -  -
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But what if it asked for "cars"? Are you supposed to click on the box [?] with the smidge of a fender and a tire?
-  -  -  -
+ + + +
+ +  - -
+ ?  - -  
Should the ? box be + or - ?  Does the captcha want "zero vs non-zero" or "welllll, it's only a small bit vs clearly there."
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Same problem with the sliver of an edge of a traffic light or a fire hydrant. And is a walk light considered to be a traffic light. (I'm a human in big cities where PEDESTRIAN traffic IS traffic. But does the captcha agree with me or am I answering it incorrectly?  
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And there is also identity ambiguity. This came up in an old post (or was it a PM) with mrfisher. There are chimneys and there are vents (flue vents). Vents are not chimneys. I know that. You know that. mrfisher knows that. But do the captcha bots know that? Am I supposed to click on a vent for a chimney OR show them that I'm a human that knows the difference and not a bot that doesn't?

OP its possibla if you are on a VPN your using a service frequently used for hacks.. drop the VPN and report back in

I have the same questions and there is no place to go for answers.

There are a lot of old threads on captchas. Here's the one about chimneys vs. roof vents:
http://www.theeroticreview.com/discussion-boards/ter-general-board-12/tor-was-fine-up-until-about-a-week-ago-954845

It all depends on each hobbyist.

Dropping vpn on sites like this is a bad idea imo.  

I never fail to use a VPN to get here and have never encountered a captcha no matter what I do or how long I'm logged in.

I've tried with and without VPN to the same effect unfortunately.

It's not the VPN. I've tried without VPN (an equivalent of accessing the site naked through private channels internationally) and it's the same thing.

Yup. That's confusing as well. However if you don't select enough of the item in question, it will say try again. Selecting too much won't give you any error warning.

It's BOTH I'm fairly sure.