Someone keeps stealing the metal signs at mile marker 66.6 along two of New Jersey's most traveled roads, and authorities are having a devil of a time keeping up with the thefts.

Joe Orlando, a spokesman for the New Jersey Turnpike Authority, said officials have no idea who is taking the signs. "Maybe it's just some kids with a Devil-may-care attitude," Orlando said.

It's been happening all over the country, particularly on roads with names like Route 666. Officials aren't sure if the thefts are being committed by religious zealots upset about the number's association in the Bible with the devil, by Satanic scavenger hunters, or by college students who think a '666' sign would look cool in their dorm room.

The latest theft involved someone swiping the 66.6 mile marker sign on the Garden State Parkway's northbound lanes. It's in a sparsely populated section, far from any entrances or exits. In short, you'd have to know the sign was there and go looking for it.

But look for it — and take it — they do. Within the past two years, 66.6 mile marker signs have been stolen at least four or five times from the Turnpike and New Jersey Parkway, Orlando said.

"Given the symbolism of the number and the fact that it is obviously done in the middle of night, and in the middle of nowhere, I can safely say that I'm not eager to meet the rocket scientists doing it," Orlando added.

It costs as much as $50 to replace the signs, which doesn't sound like much, until you keep repeating it over, and over again.

A few years ago, highway officials in Morris County couldn't keep signs for Route 666 on the poles; as quickly as crews put them up, someone would take them down and steal them, often within a day or two.

Solution: They changed the name of the road to Route 665. A similar tactic might be in store for the Parkway and Turnpike mile markers, with replacement signs reading 66.61, which kind of wrecks the Satanic buzz.

In 2003, Utah, New Mexico and Colorado renamed the 194-mile-long Route 666 as Route 491 after a rash of sign thefts. Some wound up on eBay.

Pennsylvania has a Route 666, but a state transportation spokesman said few signs, if any, have been stolen.