To quote Radiohead's Thom Yorke, in a 2015 interview: "The creators of services make money ... by trawling, like in the sea - they take everything there is. 'Oh, sorry, was that yours? Now it's ours. No, no, we're joking - it's still yours.'" (It's not.)
Let's take the four things Radiohead "erased": its tweets, its Facebook posts, a Google+ profile, a website. Those things haven't disappeared, they've merely dispersed. Radiohead.com, as it appeared on Saturday, is still available on the Wayback Machine (and, one imagines, any number of other archiving sites).
The band's tweets still exist on some server at the Library of Congress and in the feeds of every user who has ever manually RTed them.
And Facebook permanently erases user data such as photos and status updates only when you delete your account, which Radiohead hasn't done.
Even then, the site holds onto things other people have posted about you, and it doesn't require third-party apps to delete your past data.
These are also, we should point out, four of the easiest online spaces to purge: Justdelete.me, an excellent directory of web companies' data retention links and policies, gives Google and Twitter an "easy" rating, and Facebook a "medium," for the degree of difficulty it takes to get data off them.
Some popular sites, including Craigslist, iTunes, Pandora and Vine, don't let you delete accounts unless you email them directly. And others, including Kik and Pinterest, will hide or delete your public-facing account - but retain all your data on its servers indefinitely.
The TL;DR of all this, of course, is that you can't actually "disappear" from the internet, even if you're a famous band. Which means that the best way to avoid unwanted digital traces may be simply to never make them.