ProtonMail recaptcha for ProtonVPN customers - why?
I use a paid ProtonVPN (PVPN) account whenever I am online, and also have a paid ProtonMail (PM) account. For about 2 weeks, PM has inflicted a 'sliding puzzle piece" recaptcha requirement every time I log on. I just did a test, and this only happens when I am using PVPN. It is not a killer issue, but since I log in and out of my services several times each day, it has become quite annoying. Can someone give me a plausible rationale for doing this? I guess I can see some possible security benefit for extra validation if a user attempted log-in using a random VPN IP, but does Proton mistrust their own service? Do they not have lists of the IP addresses they use for PVPN that they could validate against without doing any de-anonymization (which could be a potential risk from conditioning the recaptcha on the absence of a valid PVPN account)?