Given the pressure on Google and Facebook, allowing people to block tracking cookies and clear histories makes sense. It’s just possible that the echo chamber of social media has made a privacy mountain out of a molehill; perhaps the general population is far less bothered about privacy than people on Twitter. On the other hand, the platforms have more than enough user data, identifiers and stickiness to find new ways of putting relevant products and services in front of billions of eyeballs - tools their competitors may not have when their trackers have been deleted.

As such, it's a perfect pincer-pivot. The internet giants, by giving people choice, can show that the worlds of advertising and e-commerce will keep on turning while enabling regulators to legitimately report back to political overlords that citizens are not being manipulated. At the same time, competition is weakened.

It appears Facebook and Google are converging on that view. By signalling action ahead of regulators, they have very little to lose, and everything to protect. Whether they have left it too late remains to be seen. But in the absence of action, marketers will keep filling their boots... while they can.