I haven't seen one these yet (I live near Sacramento), these are put up on places like bus stops and sides of buses. Just look at what the same group does in NYC.
It's not the same as a Church putting up a Christmas message on their own billboard on Church property.
Do you see the difference? Putting up a sign on a church's billboard is probably a matter of finding the right letters and putting them up correctly. These 'freedom from religion' whakjobs are paying money to put this up in public places.
I know my Church spends a lot of time and donations to help the needy but they don't put up a sign about it. So, I don't see how you can say they are both the same, they're not.
I agree were that the case...but then, we're speaking of billboards such as these:
These are the same, would you not agree?