> I don't get what changed? We've knows Facebook tracks everything, we've known Google does the same thing.

This reminds me of the OkCupid scandal: https://www.vox.com/2016/5/12/11666116/70000-okcupid-users-d...

A researcher released a dump of 70K dating profiles and people were horrified. But this data was already accessible to anyone (just had to create a free profile) and you can be sure it was already used for analytics purpose.