Have any players even uttered boycotting the Olympics?

it might just be my ignorance but i have yet to hear any player in the wake of the situation with tibet,darfur and environmental issues,mention anything about this. and this isn't about politics,it's about human rights. one would think even federer in all of his charitable activities,would be more outspoken about this. will anybody even do anything? or will their pervading ego's get the best of them?