Andrew Seidel, a consultant with the Wisconsin-based Freedom From Religion Foundation, said he decided to take up the issue after a Pitman resident, who asked to remain anonymous, contacted him, complaining he had to pass by the sign on his way to work each day.
"'Keep Christ in Christmas' is so blatantly an endorsement of a single religious view," he said. "You can't be free to believe what you believe if the government is picking a corner, taking a side. It makes all non-adherents feel like political outsiders, and it's not OK for government to make people feel they don't belong."
Sponsored by the Knights of Columbus, the Catholic fraternal organization, the sign has been hanging over Pitman's main street each holiday season for years, with the intention of reminding residents of the religious significance of Christmas.
Dennis Merlino, an official with the Knights of Columbus in nearby Mantua, said the slogan was not designed to exclude other religious groups from holiday celebrations. He said he thought the controversy had been overblown.
"If you took a poll, I doubt you'd find many people against it," he said. "I don't know why it is that people think that because you put up a sign, you're against everything else."
Pitman Mayor Michael Batten, who owns a barbershop downtown, echoed the sentiment.
"I think it's a sign of the sad state of affairs of life in this country," he said of objections to the banner.
For now, borough attorney Brian Duffield is investigating which government entity might have jurisdiction over the sign. He said the lines hanging the sign were attached to private properties.
"I doubt they have a permit," Duffield said. "We'll have to look into it."