ABC News

The Louisiana American Civil Liberties Union has called out local police, saying they violated a woman's First Amendment rights by threatening her with sanctions after she erected a Christmas light display depicting an extended middle finger.

The woman, Sarah Henderson of Denham Springs, La., decorated the roof of her home with the bright, bird-flipping display after Thanksgiving. According to Marjorie R. Esman, Executive Director of the Louisiana ACLU, Henderson put up the display after "a conflict with her neighbors."

After neighbors complained, Henderson soon got a visit from the local police, and she soon removed the offending arrangement from her home.

"[Police] threatened her with some kind of sanctions, so she agreed to take it down," Esman told ABCNews.com. "That was an unlawful threat, but she didn't know that at the time."

Esman said that the Louisiana ACLU was alerted to the case by an article in the Baton Rouge Advocate. The organization wrote an open letter to Scott Jones, the Denham Springs chief of police.

"These actions violate the First Amendment, and we write to ensure that no such fines are levied or other penalties imposed if Henderson chooses to reinstall her controversial holiday display," the letter says. "The law on this issue is perfectly clear: the City may not restrict Henderson's expression purely because it, or Henderson's neighbors, finds it vulgar or offensive."

The letter goes on to cite legal precedent in the case of Cohen v. California, which states that the "state may not, consistently with the First and Fourteenth Amendments, make the simple public display … of [a] four-letter expletive a criminal offense."

Esman also cited a follow-up story in the Advocate in which Jones says he "will see if there is a city ordinance" preventing such a display.

"This confirms our suspicion that there aren't any [ordinances], and if there were, it would be unconstitutional," Esman said, adding that as of now, "all legal options are under consideration."

Calls placed by ABCNews.com to the Denham Springs police department were not returned.