>When the scale is huge, no other alternative way to contact exists
1. This still doesn't preclude giving a blocked user recourse or information. Like how a streaming website will say "Hey, you're using a VPN. We don't allow that" - the user's recourse is to turn off the VPN, or find a new VPN that their service won't detect.
2. The case you're outlining is different from the scenario that most users are presented with a CAPTCHA. I encounter it when I am using a VPN and Googling something with Incognito mode. That means Google has already applied some heuristics and thinks that chances are higher than normal that I'm a bot (not logged in, no cookies allowed, masking IP address) before presenting the challenge. In those cases, you're probably correct that presenting a CAPTCHA is a reasonable option. I just think it's weird to have CAPTCHA be the default/first line in many cases. Especially with the focus on things like converting users.
1. This still doesn't preclude giving a blocked user recourse or information. Like how a streaming website will say "Hey, you're using a VPN. We don't allow that" - the user's recourse is to turn off the VPN, or find a new VPN that their service won't detect.
2. The case you're outlining is different from the scenario that most users are presented with a CAPTCHA. I encounter it when I am using a VPN and Googling something with Incognito mode. That means Google has already applied some heuristics and thinks that chances are higher than normal that I'm a bot (not logged in, no cookies allowed, masking IP address) before presenting the challenge. In those cases, you're probably correct that presenting a CAPTCHA is a reasonable option. I just think it's weird to have CAPTCHA be the default/first line in many cases. Especially with the focus on things like converting users.