Kathy Sierra, from what I know of her, is an exceedingly smart and good person who has been targeted by a group of bloggers who recently posted death threats (including images) that has succeeded in scaring the wits out of her. She cancelled all her future speaking engagements due to this incident. Scary, sickening and disturbing stuff.
Frank Paynter is one of the people that has stepped up and claimed some responsibility. He and Kathy have made friends again, but the real offenders will be made public (and vilified) soon I'm sure.
There are tons of people writing about this and the one post that stood out for me was by Josh Porter at Bokardo.
Many folks are saying things like “this is the underbelly of the blogosphere�?.
No, it isn’t. It’s the underbelly of humankind. This stuff has happened forever, to all kinds and sorts of people, in all walks of life, for thousands of years. It wasn’t right in prehistory. It wasn’t right in Greek and Roman times. It wasn’t right when the major religions blossomed. It wasn’t right in Medieval times, it wasn’t right during Enlightenment, and it’s not right now.
Another point is that these events aren't necessarily new to Web. Though I haven't done the research, my bet is that lesser known people are threatened online more often than we think. In this case, Kathy has a very well read blog and lots of adoring fans. Kathy's message travels fast and with great resonance. I hate that this happened to her, but it will bring much more visibility to the issue and hopefully become a rallying point for preventing these types of things from happening the future.