Author of the linked thread here. Interesting remark. Measurement is always underdiscussed, including in my research. Any idea about how RTB data (or data similar to it) could flow to a spytech firm via MMPs?
My thought with the original Twitter link above was that most of that is fake data, which for actual surveillance wouldn't help much. MMP data is way more likely to be the real deal. MMPs provide this data to most ad networks and MMPs via postbacks of ALL installs (not just the ones related to the ads shown).