@woozle So far it's been primarily through tools like Privacy Badger and Multi-Account Containers. Privacy Badger at least should come with the browser and be on by default. It's essentially what Apple's now building in to Safari (the Privacy Badger functionality at least).
Tracking needs to be opt-in. Europe's "We use cookies, opt in or fuck off" is utterly worthless. We need laws against non-opt-in tracking, not laws forcing web sites to tell people meaningless things.