What does this claim look like? I mean, I’ll bite if all they claim is that they offer 100 % privacy from their end, so they don’t do anything with my data. That’s good enough for me.

And promoting proprietary software in the form of JavaScript, is that an inherently bad thing apart from being proprietary?

Just curious because you seem rather emphatic about this so I’d like to know more about your thoughts, since I am a potential customer.