1. Shortly: this is what may happens to you (funny version)
2. Clickjacking webcam: what is that?
3. Activating Mac webcam with remote control: RATting
4. "The web is a window"
6. How shoud I protect myself [PANIC VERSION]?
7. How should I protect my computer, seriously?
You need to know some things, also very simple, really.
Every PC user should update periodically Adobe Flash here.
Windows users: use an antivirus like Avira, and update him every time you connect;
Mac/Linux users: keep your OS updated;
if you feel strongly paranoid and don't use webcam, you could also put a piece of tape on cam.
All users: when some webcam is working, expecially on some websites, your face or whatever you show in cam should be recorded by anyone.
Keep your privacy, please!