[melesian]

It's not simply about what you SEE. It's about tracking what sites you visit, where you are, what information can be collated to profile you in any and every way: your political preferences and likely interests can be gathered with some degree of probability from such things as your taste in music. Google buys your purchase history. Facebook has over 4,000 data points on you even if you don't use Facebook (use WhatsApp? people you know do? you're in their phone's address book?). Microsoft, Amazon and others likewise.

The data are for sale.

This is how Trump got elected and the UK got Brexit. Microtargeted political messages to persuade a proportion of the population to vote the way the very rich wanted them to vote.