Reading these comments above, it seems that some users have compiz installed on too low graphic card/chipset models, and got crashes (at least its easy to understand that crashes are the highest possible probability)
So activating compiz on such hardware should not be possible (either compiz should detect graphic hardware before beeing activated, or simply not installable, or nouveau need to deactivate compiz before crashing)
Reading these comments above, it seems that some users have compiz installed on too low graphic card/chipset models, and got crashes (at least its easy to understand that crashes are the highest possible probability)
So activating compiz on such hardware should not be possible (either compiz should detect graphic hardware before beeing activated, or simply not installable, or nouveau need to deactivate compiz before crashing)