They have a lot to gain. Many analysts are saying that surveillance, or the perception of complicity with it, is going to lose international customers and have other negative effects on business partnerships.

https://www.eff.org/deeplinks/2013/11/how-nsa-mass-surveilla...

I agree that for the most part, geeks at these companies are as opposed to surveillance as people outside - probably even more so. However, usually, it's business impact that turns private opinion into official corporate policy.