It's worth noting that the author (Christopher Brunet) is an intentionally inflammatory right-wing commentator, not an economist. Do not take this blog seriously.
The short story: EJMR is an anonymous forum used by economists that occasionally has job market rumors, but is more often filled with sexism/racism/etc. They anonymized using a hash of IP + thread ID with no salt. Three economists realized you could identify the location of many posts and wrote a paper showing how much of the toxic language came from top university IP addresses. Naturally people on the forum (and sympathizers like this writer) are collectively losing their minds, realizing that they may not be as anonymous as they had assumed. So they are threatening legal action, claiming "doxxing", and writing stupid blog posts.
So in other words they did get doxxed, you're just happy about it. You say not to take the blog seriously but then affirm his claims
It's very short-sighted to gloat about someone else's anonymity being lifted just because you don't like them. You may not think you have something to hide today, but that doesn't mean you'll have nothing to fear tomorrow
The claim that this is "Every economist on Mastodon" is of course a stupid exaggeration, but it's still a significant enough event to warrant reporting
Saying they "realized you could identify the location of many posts and wrote a paper" is downplaying the situation. The authors essentially ran a lookup table attack, computing over 3 quadrillion hashes to crack the IPs. The website owner incorrectly thought and claimed this would protect IPs, which are PII.
The short story: EJMR is an anonymous forum used by economists that occasionally has job market rumors, but is more often filled with sexism/racism/etc. They anonymized using a hash of IP + thread ID with no salt. Three economists realized you could identify the location of many posts and wrote a paper showing how much of the toxic language came from top university IP addresses. Naturally people on the forum (and sympathizers like this writer) are collectively losing their minds, realizing that they may not be as anonymous as they had assumed. So they are threatening legal action, claiming "doxxing", and writing stupid blog posts.