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.