From The Intercept's "how to pass on tips" page [1]:
> We’ve taken steps to make sure that people can leak to us as safely as possible. Our newsroom is staffed by reporters who have extensive experience working with whistleblowers, as well as some of the world’s foremost internet security specialists. Our pioneering use of the SecureDrop platform enables you to communicate with our reporters and send documents to us anonymously.
I think it's shocking that nobody at The Intercept was aware of the yellow dots, or other metadata (eg printer-specific output artifacts) that might facilitate the revelation of the anonymous source. This is so careless of them that I'm led to believe that they don't have a formal scrubbing step at all.
Of course, I might be biased a bit here because I dislike Greenwald so much for how he handled the Snowden leaks. The risks Snowden took and the sacrifices he made are incomparable, but "it took Greenwald several more months and help from experts before he could learn relatively basic tools like PGP encryption."
[1] https://theintercept.com/leak/
[2] https://www.dailydot.com/layer8/edward-snowden-gpg-for-journ...
Edit: I think it's shocking because assisting whistleblowers and protecting their anonymity seems central to The Intercept (which I believe is commendable), so they, of all people, should know better -- if not best.