[Lancey Howard]

That is unless you would want to be be sued for refusing to rent a piece a property that you owned to Planned Parenthood.

Or, unless you are a baker who doesn't want to be sued for refusing to bake a "wedding" cake for a couple of carpet munchers or turd pokers.
Oh wait...

[OKRA2012]

It depends on the laws of the jurisdiction in question.

In most jurisdictions the baker can refuse service for a gay wedding, while in some jurisdictions he cannot.