That's not covert if the blocker can see them. The headline had me imagining the Guardian site was proxying tracking data to these 58 other trackers from their

That's not covert if the blocker can see them. The headline had me imagining the Guardian site was proxying tracking data to these 58 other trackers from their own client-side tracking that goes back to their origin. But nope, just the usual tracking script/cookie/beacon nonsense.