I wrote a couple of weeks ago about not being weak when people decide to leave your company.  I wrote that post to give an alternative stance to the usual approach - thanking them for their service publically, having a go away ceremony, all that crap.

Of course, you can take the "Us vs. Them" approach a little too far as well.  Here's a little story I'd like to tell, about one CEO you know so well (h/t Beastie Boys, RIP Adam Yauch).  From the Wikipedia bio of Mark Luckovsky:

"Mark Lucovsky has stated that Steve Ballmer, on being informed that Lucovsky was about to leave Microsoft for Google, picked up a chair and threw it across the room, hitting a table in his office. Lucovsky also described Ballmer as saying: "F**king Eric Schmidt is a fu**ing p***y. I'm going to fu**ing bury that guy, I have done it before, and I will do it again. I'm going to f**king kill Google," then resumed trying to persuade Lucovsky to stay at Microsoft. Ballmer has described this as a "gross exaggeration of what actually took place."

Lucovsky worked on the Microsoft .NET My Services product (codenamed Hailstorm) prior to moving to Google. At Google, he served as a Technical Director for the Ajax Search API. He joined VMware in July 2009.

Too good not to share. You can take the whole Us vs. Them thing a little too far.  Stop when you're thinking about calling the other company's CEO a derogatory name.  And when you want to throw a chair.  

Pens?  Yes.  Chairs?  No.