(My interpretation of events.)

Philosophically she's one of the least divisive thought leaders I've come across. (She would hate the term "thought leader," and never claim it. I just use it as a shortcut to describe somebody who has a specific philosophy/advice, above their own persona.)

In fact, I've yet to meet anybody who actually knows her ideas, that even disagrees with them, let alone doesn't like her. Maybe this is because her work is not "against" anything, and generally positive/enthusiastic.

(Unlike say, somebody who is a startup bootstrapping evangelist. That person would probably talk about how evil venture capital is, and end up being very divisive. Kathy Sierra's work involve no such equation, though funnily enough, she says that divisive work is usually a good sign. DHH loves and quotes this of course :D.)

Back to the incident: There was a forum of some people who thought they were performing a public service by calling out some semi-famous thought leaders. This wasn't limited to female people, but there were a few objects of their ire that were female, and the trash talk was definitely gender specific.
This forum, not unlike 4chan, was more caught up in its own dynamic and emotion than having a specific ideology. Nobody could really say what they were for. They talked trash constantly.

It also probably attracted new members who were 10x more sketchy/scary/clueless than the OG crowd. This is a common community dynamic.

Some people took the Kathy Sierra trashing way too far, including some too-elaborate-for-comfort graphic depictions.

Was it just a harmless troll? Was it somebody new and insane and serious? Was it really about Kathy Sierra, or was it just bad luck to be chosen as the object of attention, a la 4chan?

The threats spread outside of the site, got more specific/direct/ violent, and Kathy Sierra cancelled a major appearance (the reason I know this story kinda of well is only because I was attending that event, etech, and it was very special occasion/big deal for me, and I paid extra to attend a tutorial by her :D)

People who never specifically admitted to being involved in the initial trash-talking, jumped in to pish-posh the fear/concern over the events, and defend free speech.

As far as I know, they never figured out who sent out the death threats, but did figure out some of the horrible trollers. Possible, but unproven that they were the same folks. Possible, and hopefully not true, that the initial stuff was garden-variety trolling, and later stuff was a seriously dangerous crazy person.

Some people have dismissed the incident as overblown, blending the off-site death threats, with the initial forum trolling.

I personally think they're two separate conversations. I think the initial trolling was horrible and depressing, but somewhat normal. But that the later threats were too disturbing and rare of an occurrence to be dismissed.

sidebar:
Though the death threats did lead to a talk cancellation, and curtailing of her blog, it did not make her retire.
She's given many talks since (duh, the top of this thread is about a recent great one).
And her recent departure from Twitter is not the result of anything gnarly happening.

sidebar ps:
Almost any post about a Kathy Sierra talk/essay/quote ends up being about missing her/ the unfortunate death threat incident.
This is totally understandable.
That said, I hope nobody misses the opportunities to learn from and benefit her transformational philosophies.
Elsewhere in this thread I discuss the actual video, and how her ideas are as important as Lean, in terms of how they should influence what we do.