I think a big reason for this is that PDF editing tools are just pretty terrible.
PDFs are meant to be a presentation document format, not an editable document format. I have some experience editing PDFs, and it's difficult to make significant modifications. Editing small sections of text or replacing a date is fine, but once you try to start editing entire paragraphs or changing the layout, it quickly becomes unmanageable. The kerning looks weird, the spacing between words looks off, and when you look into it you realize the the sentence you're trying to edit is actually split across a dozen text objects. For these it becomes almost impossible to edit without destroying the spacing, so you just give up.
And the approved way to edit these PDFs is via Adobe Acrobat Pro, which costs $20/month (ugh), which I'm not willing to pay for.
So I think this is why we just don't see that many PDF forgeries. The editing tools just aren't very good. Maybe it's different now we can just ask Claude to edit our PDFs for us.
I agree that you won't find forged PDF documents in the wild with any type of frequency, but they are forged in private settings. Forged or doctored bank statements are relatively more common. FinCEN identifies altered bank statements alongside W-2s, tax returns, gift letters, and employment information as examples of documents involved in mortgage fraud [1]. In March 2026, a mortgage loan officer was even charged by federal prosecutors with altering and creating bank statements to make borrowers appear qualified for a mortgage [2].
I'd say the reason for this is that PDFs are not viral like images or videos. I don't think any of the technical arguments are strong enough.
If you want to forge a PDF, you do it because you have a private target in mind. Financial fraud, corporate espionage... There are other settings but people don't just share PDFs around for you to see a deluge of fake ones.
The flip side to this is that when you do come across a forged PDF (and I have!), they can be really, really effective. Nobody expects them. There are usually tells in the metadata, but... there don't have to be.
Not quite the scenario described (it wasn't an academic paper), but https://mjg59.dreamwidth.org/73317.html is my experience of dealing with a forged PDF. Part of the reason it's rare is that it's actually very hard to do it well!
> "And when you do find a PDF claiming something malicious, [..] it’s always a ‘new’ PDF, which is forthright about it being a new unpublished ‘white paper’ or somesuch, and doesn’t purport to be a published paper."
> "Whereas, if you were so epistemically careless with images on, say, Facebook, you would wind up with a folder stuffed full of lying images which have been Photoshopped, claimed to be things other than what they are, ‘deep faked’, etc"
Maybe because a paper is a comprehending medium, expecting the reader to understand its source and interpret the content on a more intellectual level, whereas effective images/videos are usually framed to be understood immediately.
i.e. if I want to convince people that lizard-people live among us and I want to manufacture proof, my demographic probably responds more to images with a lizard than a reinterpreted academic paper...
Offtopic but the damage caused to an entire generation by Gwern's nicotine article is truly astounding. Obviously he's not responsible for the actions of others and it was written with good intentions but wow.
Gwern, in case you are reading this, there's a typo in:
> (In the rare cases anyone tampers with PDFs, it quickly turns into a technical morass and he-said-she-said, and requires several orders of magnitude more effort to prove than to do; consider the hoops epxperts had to jump through in the Craig Wright cases, or even just a landlord editing a contract—where the contract was done through a digital document timestamping service!)
Ok this one actually baffles me -- anyone have the energy to explain what I'm missing? The repeated concern about forged scientific papers doesn't really track, but that's what academic institutions are for, at least in part.
If someone were to share a preprint PDF that I don't believe, my instinct would be to double-check it against the institution associated with its publication. If it was never published then it's basically just a screenshot of a blog post.
Ohhh okay the opening makes more sense now. The blog above is publishing papers in form of blog posts as a protest against scientific publishing. I love the energy, but ruminating on how weird it is that so few people take advantage of the thing that you're weird for doing in the first place feels... obtuse?
>PDF forgery is striking because it’d be so easy to do: find a useful research paper, edit it in any of the many PDF utilities, upload anywhere, wait for people to copy it (as they do), then take down yours; now you have an authoritative peer-reviewed research paper floating around the Internet with no links to you, in the perfect crime. (Or better yet: upload it directly to Libgen/Sci-Hub and let everyone else redistribute it.)
Seen as (unsigned) PDFs are basically images of documents, it's wild to claim that there are no forgeries, anyone doing a good ole fake document, fake diploma, fake wire transfer, fake articles of incorporation, etc... is using a pdf for faking. A nigerian prince scam sending an attachment mentioning 15.000.000$ locked up in inheritance would constitute a PDF forgery.
PDF Forgeries Are Surprisingly Rare (2022)
(gwern.net)42 points by 1317 20 September 2026 | 34 comments
Comments
PDFs are meant to be a presentation document format, not an editable document format. I have some experience editing PDFs, and it's difficult to make significant modifications. Editing small sections of text or replacing a date is fine, but once you try to start editing entire paragraphs or changing the layout, it quickly becomes unmanageable. The kerning looks weird, the spacing between words looks off, and when you look into it you realize the the sentence you're trying to edit is actually split across a dozen text objects. For these it becomes almost impossible to edit without destroying the spacing, so you just give up.
And the approved way to edit these PDFs is via Adobe Acrobat Pro, which costs $20/month (ugh), which I'm not willing to pay for.
So I think this is why we just don't see that many PDF forgeries. The editing tools just aren't very good. Maybe it's different now we can just ask Claude to edit our PDFs for us.
[1] https://www.fincen.gov/mortgage-loan-fraud
[2] https://www.justice.gov/usao-mdfl/pr/licensed-mortgage-loan-...
If you want to forge a PDF, you do it because you have a private target in mind. Financial fraud, corporate espionage... There are other settings but people don't just share PDFs around for you to see a deluge of fake ones.
> "Whereas, if you were so epistemically careless with images on, say, Facebook, you would wind up with a folder stuffed full of lying images which have been Photoshopped, claimed to be things other than what they are, ‘deep faked’, etc"
Maybe because a paper is a comprehending medium, expecting the reader to understand its source and interpret the content on a more intellectual level, whereas effective images/videos are usually framed to be understood immediately.
i.e. if I want to convince people that lizard-people live among us and I want to manufacture proof, my demographic probably responds more to images with a lizard than a reinterpreted academic paper...
Can this actually be done without an ISBN or DOI number?
> (In the rare cases anyone tampers with PDFs, it quickly turns into a technical morass and he-said-she-said, and requires several orders of magnitude more effort to prove than to do; consider the hoops epxperts had to jump through in the Craig Wright cases, or even just a landlord editing a contract—where the contract was done through a digital document timestamping service!)
Specifically "epxperts"
If someone were to share a preprint PDF that I don't believe, my instinct would be to double-check it against the institution associated with its publication. If it was never published then it's basically just a screenshot of a blog post.
Ohhh okay the opening makes more sense now. The blog above is publishing papers in form of blog posts as a protest against scientific publishing. I love the energy, but ruminating on how weird it is that so few people take advantage of the thing that you're weird for doing in the first place feels... obtuse?
Seen as (unsigned) PDFs are basically images of documents, it's wild to claim that there are no forgeries, anyone doing a good ole fake document, fake diploma, fake wire transfer, fake articles of incorporation, etc... is using a pdf for faking. A nigerian prince scam sending an attachment mentioning 15.000.000$ locked up in inheritance would constitute a PDF forgery.