My personal ethics would prevent me from developing surveillance tools, anything which is mostly military in nature, or any kind of video game which requires a heavy investment of time.
I do believe in general that people are responsible for the consequences they create even if they could not have possibly predicted them. I certainly don't think that Blizzard should be punished for the death of that man. I would only hope that when they heard the news that as individuals they stopped and spent a couple of quiet minutes asking themselves if what they are doing contributes to improving human society or not.
How many must die playing Starcraft waiting for Starcraft 2 to come out?
:) (I personally played something like 2000 games of it)
I know some guys who are doing work for Homeland Security. They don't talk much about what they do. I think "preventing another terrorist attack" sounds better than "snooping into everybody's life" -- although I'm not sure in practice there is a difference.