I second the suggestion to contact the FFRF. Send them some pictures, fill them in on the details and let them know that you wish to remain anonymous if you fear retaliation.
Okay, I am not an American, so my views on this count so much in this matter.
Why not allow them their fantasy displays, openly and freely and vigorously counter the actual changes in public policy they would bring about. If they want to bring prayer in schools, let them but force them to bring all forms of prayer, Hindu, various shamanistic prayers, Satanic chants, wiccans, etc. Actively search out new religions and show these religions the same favour as the Christian ones, and keep these beliefs in the public eye. Soon I think you will find that they will decide that all religions should stop and be kept at home, where they should be.
Because you would then still be excluding Taoists, Atheists, etc. who wouldn't have a prayer to say.
There is another concrete problem. The U.S. Bill of rights says that congress 'shall make no law respecting an establishment of religion or preventing the free exercise thereof". By doing things like granting prayer for specific religions, no matter now many of those specific religions, they are respecting an establishment of religion. They are putting themselves in the position of saying what is a valid religion and what is not. To enforce such an inclusive prayer policy as you suggest, (not to mention that this still excludes atheists, Taoists etc.) there would have to be some kind of minimum list that had to be included. By doing that, someone will inevitably be left out, therefor putting a government entity such as the school in the position of showing favor to some religion or religions over others. (Once again violating the establishment clause.)
The only way to comply is for all public entities and funding to remain entirely non-religious. On the same note, that public funding or entity may also not be used to place a large banner or monument that explicitly says there is no god. That too would violate the establishment clause. Government must remain neutral.
Let me ask you this? What is it that you are wishing to accomplish through doing this?
If you wish to make a stand on a legal and social issue and do not fear reprisal and being ostracized then by all means, go for it. But if you are doing it solely to have a cause to fight for in the name of religious freedom, all the while being aware of the lack of support that you will have in your community, as well as the potentially adverse to dangerous reactions toward family members and yourself that this could provoke, you need to decide if the reward is worth the risk?
In the best case scenario, lets speculate and say that you discover it to be public property. You initiate a suit or a campaign to have the scene removed, you battle the forces that be, whether it is Churches, or City Hall, or both, and you win your fight. The Nativity scene is removed. What will the social, financial, and physical costs be to you, not only in the short term, but in the long term? How will the community see and treat with you? Will you have reduced your quality of life for the sake of pressing forward a freedom?
No one likes seeing that sort of garbage around on one's street, evoking greater reinforcement of superstition. But in the grand scheme of things, one must also look at the over all situation. I would not like to stand in the middle of an enemy landscape and proudly announce, "Yeah I got your precious Religious crap removed permanently! What of it?" As the forces of evil surround me on all sides, and in affect ( even though that descriptive sounds a bit melodramatic ) that is exactly what you would be doing if the heavy religious presence is that great!
Ultimately you and your family must live there. What sort of lifestyle will you lead if you enage in this battle. And worst case scenario, suppose that you loose the battle. By and for whatever means. Then what? Nothing will have changed AND you will have the wrath of the religious heavy majority breathing down your neck.
I would advise that you weigh it out, consider your family and friends and children, and pick your battles wisely. Sometimes silent concession is better than vocal success. If you do go for it, make sure that you have as much media and Atheist support as you can get, because, win, loose, or draw, things will get ugly! Best of luck to you and yours!
Oh and just a little footnote about all of this advice pro and con,... NONE of us have to live with the consequences of the advice that we give you. It is easy for us to say, "Hey man!, don't do it!", or "Screw those Religious folks! Go for it!"
In the end, you will have to deal with the punishment and rewards of whatever path you choose to take. Remember to keep that in mind as you read all of the opinions shared with you! Cheers mate!
It violates the constitution though. Generally, the public offices that put up those displays also would reject other non-Christian displays. (With the occasional exception of Hanukkah displays)
It also does harm. How many theists have we argued with individually and collectively who have used the argument "It says 'In God We Trust' right on our money!" or "The Pledge says 'Under God'!", as if those things weren't fairly recent developments. As if they were there from the beginning. That argument is then used to justify religious reasons for social policies. (Such as banning gays from the military, or marriage inequality, or banning atheists from public office.)
I'm with you here. It's not the same thing. It would be if, say, people were asked for their religious affiliation upon getting on a bus, and they were all honest, and the atheists were sent to the back. Or atheists had hoses turned on them for protesting discriminatory laws. Black people couldn't drink from the white fountain without being questioned, but you couldn't do the same for atheists. We look like everyone else. You can't just pick us out of a crowd.
I will however say that more than social, there is institutional discrimination. The Texas State Constitution among several other states, bans those who don't believe in 'almighty god' from holding public office. Of course this violates equal protection and the establishment clause, but that doesn't always seem to matter I guess. -_-