Things that are okay to criticize: Nativity scenes on government property.
Things that are okay to criticize only if you’re a complete asshole: Nativity scenes on your neighbor’s lawn.
That’s what an anonymous letter-writer did to Kristen Hunter‘s family in Newton, Massachusetts:

The “neighbors” who sent the letter wanted to point out that the entire neighborhood is not Christian and may not want to look at their decor, especially given that it is “cheap, tacky and kitschy.”
The note stated that the “neighbors” have held their tongue in the past, but felt it was important to make their concerns known this year. Because “not everybody in the neighborhood is Christian” they believe that people do not want to “see such a flagrant display” of Christian beliefs.
The letter also stated that the decorations were tacky, calling them a “terrible eye-sore on the neighborhood.”
“All religious matters aside, your decorations themselves are beyond tasteless,” the letter said.
…
The “neighbors” conclude the letter by telling the family that they are free to worship and celebrate however they’d like and they are even “free to have bad taste” but they ask the family to do those things in the privacy of their own home.
We don’t know if the letter-writer (and I’m assuming there really was a letter-writer here) was an atheist, but it looks that way. If the letter is real, then that person’s just being a jerk. And Hunter was as classy as ever, especially with her reaction to this question:
Reporter: The letter came anonymously. They said, “How would you like to drive by an anti-Christian display?” What did you take [from that]?
Family member: You know what? If that’s what they wanna do, that’s fine. People have the right to celebrate.
Of course, Fox News is jumping on this story because War on Christmas.
(Thanks to @imjustasteph for the link)