I'd love to set up a web page / app that just raids every cookie it can find, and gleans as much data as possible on a user with as little direct user interaction or authorization as possible.
Like, you show up on a chrome browser, it tells you about the smart TV on your home network, 3rd party cookies gets your Adobe audience Manager ID and that displays your targeted ad demographics.
Almost like "Red team" privacy work. I'm doing Blue team privacy work rn and it's less fun.