I know everyone love to hate on the industry but I think with such firepower, I'd go for a "takeover" of the 3rd parties (read middle men) in Online Advertising. You probably have decent capabilities to detect fraud while building a privacy minded tracking system where the user can manage its personas.

While the ITP (Safari's -and maybe Chrome soon-- attempt to regulate tracking) initiative is on paper a good idea, I'm not convinced it's going to deliver.

Barging in with an OpenRTB v4 (current version is V3) that delivers on that - and maybe cut the middle men, that could be neat for every one : publishers, consummers and advertisers.