SUMPTER TOWNSHIP, Mich. (APBnews.com) -- An African-American couple who moved to this rural community several years ago to escape the grind of the city have been terrorized by threatening, racially tinged messages that have mysteriously appeared on television screens in their home, federal authorities say.

"We're investigating this as a civil rights violation," said FBI Special Agent Dawn Clenney. "I've never seen anything like this before."

Charlotte and Judge Smith, who share their remote eight-acre homestead with their 13-year-old grandson, returned home from vacation last month to find that someone had tampered with their alarm system, authorities said. They notified police, who found no sign of forced entry, nor was there anything obviously missing from the home.

But that was just the beginning of what authorities are describing as the oddest case of racial harassment they've ever encountered.

Channels change, messages appear

Within a few hours, the Smiths discovered that someone had taken control of their televisions, which are hooked up to both a nationwide satellite TV service and an Internet provider.

Channels would change, seemingly without cause, authorities said. In the middle of the night, a television would mysteriously turn on at high volume.

Then, authorities said, messages, apparently typed on some sort of remote keypad, appeared on the television screens in the family's living room and den. The messages contained racial slurs and threats, Clenney said.

Authorities said that an enraged Charlotte Smith reported that she yelled at her television on one occasion, only to have a message flash across the screen reading, "Shut up, Charlotte."

"The family has been terrorized," Clenney said.

Perpetrator close by?

Local police, unable to get to the bottom of the case, turned it over to the FBI. Federal agents inspected the house, the family's satellite dish, and reviewed tapes the family had made of the harassing messages, some of which seemed to indicate that whoever was behind the remote harassment was watching the Smiths.

Bob Mercer, a spokesman for DirecTV, the satellite company that provides service to the Smith, said it marks the first time a customer has complained about harassing messages suddenly appearing on television screens. The company is cooperating with the FBI's probe, he said.

"We want to get to the bottom of it," he said.

Authorities suspect that whoever is taunting the family has been doing it from close by, perhaps by using a short-range remote keypad similar to those offered by WebTV.

Seamus McGraw is an APBnew.com staff writer (seamus.mcgraw@apbnews.com).