This page shows whether different Bitcoin sites serve the original Bitcoin whitepaper or an edited version of it. Once an hour we calculate SHA-256 hashes of the files and compare them with the hash of the original whitepaper (that would be b1674191a88ec5cdd733e4240a81803105dc412d6c6708d53ab94fc248f4f553).
There have been some suggestions to alter the whitepaper hosted on bitcoin.org (e.g. GitHub Issue #1325 is still open). We believe that editing an academic paper and rewriting the Bitcoin history in order to accommodate someone's business interests is downright unacceptable.
Also there are null-data outputs which contain the hash as hex. The current version of our search engine doesn't yet have support for filtering scripts by hex values, but since the hex value can be represented as binary text, we can search by alphanumerical parts of this text. Examples: 90947865:0, 127382188:1, 146223515:0
More importantly, there's transaction 54e48e5f5c656b26c3bca14a8c95aa583d07ebe84dde3b7dd4a78f4e4186e713 which contains the pdf file itself. Here's an instruction on how to parse it. It may be possible to edit the whitepaper on some websites, but it's not possible to alter the blockchain.