Earlier quoted context omitted.
There is another theory which states that this has already happened.
JWZ will replace links from HN to his site, jwz dot org, with an NSFW image and an insult. It does this based on the Referer: header, so people using Firefox in private browsing mode aren't affected.
*'network.http.referer.spoofSource' in about:config : "true = send the target URL as the referrer"