Nobody is setting up "privacy-friendly" frontends to track browsing data that they couldn't otherwise get without access to Google's/Twitter's/etc. logs? Because I think they are.
Nothing. An acquaintance of mine develops a third-party frontend explicitly marketed as a privacy-friendly alternative and actively looks at lots of user data (which includes the full name) without disclosing. I honestly believe that it's only done for improving the service (and it helps tremendously) but I can't get through with arguing that this should be transparent.
You could notice by closely reading the source code.