Somehow I got it in my head that jwz implemented it. And I'm not the only one. But I can't find actual proof of the evil deed, and jwz in fact denies it -- although he does take credit for adding "MilSpec blinking". It seems that at worst jwz was responsible for eventually adding it to the linux version of Mozilla. While the original implementor fessed up last year, and actually got into mozilla's credits for it at long last: http://weblogs.mozillazine.org/gerv/archives/2009/03/credit_...
Urk, now I'm remembering one time when I walked by jwz somewhere in SoMa, and thought "if he wasn't on the other side of the street already, I'd have to cross to avoid that evil blink tag creator". And now I'm feeling all regretful. Will the pain that tag inflicted on the world never cease?