A California man’s neighbors don’t know he’s a convicted sex offender, but the man says he’s being forced by the state to warn children to stay away from his house on Halloween.

“Please do not disturb. We do not participate in Trick or Treating,” reads a sign issued by the Chula Vista parole officer, according to attorney Janice Bellucci. Bellucci is representing an unnamed man in a lawsuit against California for Operation Boo, a program that requires paroled sex offenders on Halloween to remain in their homes with the exterior lights off, offer no candy, display no decorations, and keep doors closed to anyone but law enforcement.

While the sign does not reference a sex offense, Bellucci says the message is enough to damage her client, who was convicted of a sex crime not involving a minor in 1985. California agreed to remove his name from the publicly available sex offender registry given the time and nature of the crime.

Bellucci’s lawsuit does not take issue with the entire Operation Boo program, only the sign that her client was asked to post outside his home, she told The Daily Beast.

But the California Department of Corrections and Rehabilitation, which is in charge of Operation Boo, has denied responsibility for the sign.

“Affixing a poster to one’s home is not a statewide policy of Operation Boo,” a spokesperson told The Daily Beast.

The signs might have been distributed by a parole agent acting outside their jurisdiction, Bellucci said.

Advocates for reforming the sex-offender registry say programs like Operation Boo make offenders vulnerable to attacks from the public. Under the California Megan’s Law, people can search an online database for registered sex offenders in their neighborhood. While the database allows parents to learn of potential threats in their area, it also reveals sex offenders.

“The public sex offender registry and residency restriction laws do not protect children but instead ostracize and dehumanize individuals and their families,” Bellucci’s organization, the California Reform Sex Offender Laws says online.

California, with its strict sex offender laws, has a history of vigilante justice against offenders. In 2012, a San Francisco man was acquitted after beating an elderly man who had allegedly molested him as a child. In 2010, a convicted sex offender was attacked with a sledgehammer in his own home by a man who said he had been molested by him as a child and found his address online.

Opal Singleton, president of anti sex-trafficking group One Million Kids says she supports Operation Boo, but not a provision that would require sex offenders to advertise their status.

“I would be opposed to that because I don’t think that’s helpful. The name of the game is keep the door closed and the light off,” Singleton told The Daily Beast. “A sign might encourage vigilante behavior.”

Bellucci argues that requiring sex offenders to post signs outside their homes is state-sponsored discrimination, no matter what jurisdiction is requiring it.

“I know for myself, I talked to his parole officer, and the parole officer required my client to put the sign on his home,” Bellucci said. “Whether it’s a CDCR agent acting outside their authority, we don’t know. But when my client is told ‘You must do this or go to jail,’ that’s a cause of concern.”