When Google has the ability to levy taxes, things will be very different all over.
You are aware that Google scrapes almost every page on the internet, without having any agreement with most of them, right?
Yes, you can add noindex and robots.txt to tell them you'd like to opt-out, but:
a) That only works so well, and b) they're default is to use your page without your permission.
They're lucky if they're worth 1/10th their peak valuation currently. So now they're going to stretch in any direction they can for a couple bucks before the lights go out or they're force-sold by the VCs to whatever company will buy it for spare change. Maybe they're hoping Google will open up their pockets and take care of that problem.
Either way, this is the last gasp of a failed (entirely worthy) experiment at getting the masses to annotate everything.