You can find some pretty interesting improperly redacted documents all over PACER. Usually it's defense attorneys who don't realize that blacking out text in Adobe doesn't remove it rather than the government though.
There's one about a Colombian paramilitary leader/drug trafficker turned informant which improperly redacted all the people he informed on: https://storage.courtlistener.com/recap/gov.uscourts.dcd.184.... This is from like a decade ago but goes to show how this kind of thing can literally put people's lives at risk.
That's not a redaction (these kind of pseudonyms in court filings are different from redactions and are often more about avoiding formal direct statements associating an entity than about secrecy, and are often easily penetrated—e.g., "Individual-1" in the Michael Cohen case), and while one might infer from the interaction of the subject with an SVR TOR server that Foreign Country-1 is likely to be Russia, there is nothing in the affidavit that asserts that the TOR server in question was operated by Foreign Country-1.
Yeah, it was fairly apparent earlier in the complaint what country they're talking about, but that was funny to find. I'm sure it's not the first time footnotes accidently leak info that is supposed to be redacted!
Here's one https://storage.courtlistener.com/recap/gov.uscourts.nysd.42... for the sentencing submission for https://en.wikipedia.org/wiki/Paul_Le_Roux which reveals some pretty personal and operational information.
There's one about a Colombian paramilitary leader/drug trafficker turned informant which improperly redacted all the people he informed on: https://storage.courtlistener.com/recap/gov.uscourts.dcd.184.... This is from like a decade ago but goes to show how this kind of thing can literally put people's lives at risk.