Cheaters Multiplayer and Security

I love Python for many reasons and I’m starting to love Panda3D…
But there might be some problems ahead of me.

I’m learning Panda for a week now. And I think the best way of learning about something that can be used in many ways ist to choose one way.

I’ve decided to write a FPSS - First Person Space Shooter for Multiplayer.

I started to read myself into the networking functionality of Panda(already got movement, thanks to David, and some collision detection, thanks to the manual and some samples in the forum) when I realized, that a game in soure code is extreamly vulnerable to cheats.

Now to the point of this post:

Did you ever think about measures to prevent cheating in your network capable games? Or does someone have an idea on this topic?
I know I’m far from completing even a sample code to my game idea, but this could become a major issue.
Preventing cheats is easier with closed source in my mind.

You might want to take a look at this thread