Spoofing — the practice of sending out fake caller ID information to disguise the caller’s real identity — is legal, so long as it’s not done to deceive or harm anyone. Reporters, victims of domestic abuse, human rights organizations, all legally use spoofing to protect their locations or sources. This sort of trickery is definitely not allowed when it’s deployed just to make harassing phone calls to your ex.

The FCC has filed a Notice of Apparently Liability [PDF] against a pair of brainiacs accused of using spoofing services to allegedly make harassing phone calls to the ex-wife of one of the men.

According to the FCC, between May to Sept. 2015, the ex received 31 calls from a variety of faked caller IDs.

For example, calls were labeled as coming from the maximum security “Sing Sing Correctional Facility,” the “New York City Department of Corrections,” and other local prisons. Using a voice modulator, the caller would say things like “We look forward to you joining us here,” or “We have a cell here for you.”

Calls also appeared to come from the ex-wife’s parents, or from the school where her child is enrolled. “How’s your mother/daughter day going?” asked the disguised voice.

The woman believed that her ex-husband and one of his co-workers were responsible for the calls. At the time, her ex was bound by a protection order limiting his contact with his former wife and her daughter.

She met with the National Network to End Domestic Violence, who then took the issue to the FCC. She also filed a complaint with her local police department in Long Island. The FCC’s Enforcement Bureau investigated, listening to recordings the woman had made of some calls.

By using a third-party “unmasking” service that attempts to undo spoofing efforts, the woman was able to demonstrate that at least some of the calls she received had been made on a cellphone number belonging to the ex-husband’s co-worker.

Investigators then subpoenaed this man’s call records and compared them to the log of harassing calls the woman had received. Each time the man dialed an access number to an online spoofing service matched up to a phone call received by the woman.

After being served a subpoena, the company that operates the spoofing service later confirmed that the ex-hubbie’s co-worker had used their product to make these calls. Local police subsequently arrested the caller, charging him with one count of stalking in the third degree and one count of aggravated harassment in the second degree.

The woman told investigators that she had no personal or professional interactions with this man. Her only connection to the caller is his friendship with her ex. She contended that the only reason this man would make these calls was at the behest of her former spouse.

Additionally, she pointed to details mentioned by the caller that could only have come from someone intimately involved with her ongoing custody dispute with her ex.

FCC investigators found a pattern of calls between the ex and his call-spoofing co-worker, including one instance where the ex called his buddy on his landline and remained on the phone while that pal placed spoofed phone calls to the ex-wife.

“The fact that [the ex-husband] purportedly did not dial the spoofed calls himself does not absolve him of liability for the harassment and stalking of his ex-wife,” reads the FCC notice.

The Commission points out that federal rules explicitly prohibit the both the direct and indirect misuse of caller ID spoofing to prevent the exact sort of case seen here, where only one party made the offending phone calls but a second party is allegedly the one directing the harassment.

The notice proposes $25,000 forfeitures each against the ex-husband and his boneheaded buddy. If that seems like a lot to you, remember that the law allows the FCC to levy up to $10,000 per violation, up to more than $1 million total. The notice explains that the $25,000 amount is in line with previous forfeitures for individual violators. The amount could drop for either of the two men if they are able to demonstrate an inability to pay.

“It is against the law for anyone to harass, defraud, or terrorize another person by spoofing or deliberately manipulating their caller ID,” said Enforcement Bureau Chief Travis LeBlanc. “Spoofing is particularly disturbing when used to trick consumers into believing that the calls are from family members or representatives of banks, creditors, insurance companies, and even the government.”

The criminal complaint against the co-worker who placed the calls is still ongoing.

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