Earlier quoted context omitted.
so if you don't pass, say, by using TOR or even just a VPN, you don't even get a chance to prove you're not a bot? Cool, really cool, I can't see that being illegal at all. EDIT: This comment is stupidly worded, please see clarification below.
Why would it be illegal? Being able to access a website (be it Twitter, Hacker News, or your hometown newspaper) is a privilege, not a right.
Say I buy a new phone and it stops working after 3 weeks. I want to contact the seller, but they only have a web contact form and I fail to get past the captcha.
This is already getting very close to being a huge legal problem, and the only reason why it's probably not that bad is that technically that website is supposed to give at least a contact address so I could just send them a letter which, while hugely inconvenient, is legally still a good enough way for me to contact them.
I'm sure if you spend a while longer you could find a few cases where the problem is even worse (also considering more than just one legal system).
So what I should have said: Using this technology to block users from the wrong endpoints could end up being illegal.
For context: I'm talking German laws here.