The type of monitoring used was disclosed as was the "likely cause" of me being flagged. This wasn't a secretive kind of thing. Of course one can't "know" anything as it's a black-box. But it's not a stretch to see how such systems may conclude, from automated profiling, that users of privacy-centric services are more likely to be associated with fraud and hence flagged. This also represents a more general issue with the application of machine learning.
You're basically saying that you've been caught up in some surveillance dragnet/watch list, and that you have no proof but think it is for for using ProtonMail on a government website.
When your payment was declined, the company 1) had access to this watch list that you're on, 2) was able to share with you that you were on a watch list, and 3) you were able to figure out why this is. This sounds very unbelievable to me. The data that comes from programs like this isn't generally being passed around to businesses, and if it is, the support folks are not going to be in the know.
It still sounds more like you're being hit by algorithmic blacklisting than that you're on some secret not-secret blacklist. That, or you got added to a public sector blacklist, by some security company because you use ProtonMail which has issues with abuse by fraudsters.
No, you've misconstrued what I've said. I am not implying that the payment being declined by a merchant is anything related to the government. Nor am I implying that the government shared my information with any company. Nor I am on any kind of blacklist (at least that I'm aware of). Read my original post, they are two separate issues.
> The type of monitoring used was disclosed as was the "likely cause" of me being flagged
You're correct, I misremembered how you wrote that. Unfortunately, that makes it even less believable. How did you find out that you were being monitored, and why was that disclosed to you? Who disclosed this monitoring to you? Did you run some sort of FOIA request (whatever your nation's version is)? You're making a very big claim with very little to substantiate. Keep in mind ProtonMail has over 50 million users, It beggars belief that using PM is sufficient to get yourself monitored in any serious capacity.