What is it about email spam that you (gregc) are passionate about? Is it the technical/intellectual challenge of fighting email spam? Or do you feel it's your duty as a netizen to defend the net against spam? Are you just tired of seeing it in your inbox and figure the best way to make it go away is to join the cause? Something else?
As this applies to me and click fraud, to be honest, I am not passionate about it and would rather not have to deal with it. I would have much rather spent time making all aspects of processing the logs more reliable and robust than identifying click fraud. I during a discussion in my group about identifying the country of origin of an HTTP access, in response to my insistence that it couldn't be done meaningfully (because the person or program doing the access could be anywhere in the world), said that I was passionate about that (as opposed to, say, database administration techniques). I don't think so ... I just wanted to make sure people's energy was focused on pressing problems that could actually be solved. Rather than expend lots of energy on something with no practical solution, I would have preferred that AV run itself in such a way that it did not depend on being able to identify the location of a user, etc.
On a more general note, I don't think I'm passionate about any part of computer science. There are lots of things I like in computer science, but that is true of other things as well (see my interests). Perhaps the closest I've come to being passionate about something was listening to pop music countdowns (Casey Kasem, Rick Dees, and so forth). I would go to a lot of trouble to listen, even if it meant trying to tune some distant radio station.
What does passion mean to you with regards to your career? life?