When they decide it's in their best interest to do so.

Perhaps lead a vocal protest against Facebook, spread it far enough, and if it gains enough traction maybe Facebook themselves will do it. They could do it at any point and be well within their rights. Same with Apple.

I think that the overarching issue that many are missing is that our corporations are acting as our representative bodies -- we're speaking with our money as consumers -- because our political bodies are corrupt and no longer representing us directly.