this is the real answer. unless you gave the app a bunch of permissions it shouldn’t have, they cannot see what you do/say in matrix. but they don’t need to. you willingly feed them enough information through location/posts/comments/private messages/friends/contacts/+a very long list of things for them you figure out your interests and serve you tailored ads.

so you are choosing to go from having issues with those things to not being able to do it at all? I don’t understand. isn’t finding/solving the issues part of the testing you mention?

if it’s fingerprinting you care about, i’d give mullvad browser a try. it’s a firefox fork tailored to increase privacy and blend you into the crowd (as long as you don’t change any setting/install addons). it’s very very neat.

it says so in the blog post