My point is it would encourage more people to apply by trying to hack into the company's networks instead of just creating impressive mods, Valve is a game dev/platform company after all not a network security one.
Ahh, I see. Point taken. I would still hire this passionate kid and put him on the network security team. I would then make a public announcement about how the job you get depends on what skill you demonstrate. Which should be the way it works anyways. If you want to join us as a game developer then you need to demonstrate your game developing passion and skills. Either through creating mods with our SDK/platform or writing/creating your own from scratch. However if you want to join us as a network security expert then you got to beat this kid we just hired! =P
If any time you were hacked, you fired the previous network security engineer and hired the guy who just broke in, you'd have a network unusuable by legitimate users and still probably vulnerable to skilled attackers.
Who said anything about firing? How does hiring one guy on to join the team == firing of all of the previous guys? Is there a one man network security team rule at Valve that I'm suppose to know about?
If you hire somebody to your security team every time your network is compromised, and never fire anybody, your network security team will outnumber the rest of your company.