SALT LAKE CITY (AP) — Animal-welfare activists are saying Utah legislators enacted a law to prevent filming of agricultural operations to silence them. They say the misdemeanor offense is unconstitutional because it singles them out for punishment.

The Deseret News reports  that the argument is being made by People for the Ethical Treatment of Animals and the Animal Legal Defense Fund in a recent filing in federal court in Salt Lake City. The groups filed a lawsuit in July to overturn the law enacted last year.

It makes it a misdemeanor to trespass on private property to record images or sounds of a livestock operation. State attorneys asked a federal judge in October to throw out the lawsuit. They contend the activists can't show an immediate threat of prosecution.