"It's scary that people can do that, you know?" said Advantec Solutions owner James Eggert.
Eggert says their server became ineffective when someone climbed poles near Northwest 18th and St. Claire in Oklahoma City and cut 100 feet of AT&T's cable lines, just to sell the copper.
One client called later to say they're no longer a customer; others may follow.
"It's terrible for business, obviously," says Eggert. "Our customers were very frustrated for good reason."
AT&T Oklahoma spokesman Andy Morgan says they've seen a rash of these types of crimes lately, 10 of their lines have been cut within the past week.
He says a vast majority of AT&T's lines are buried, but this crime did more than hurt business.
"It's a serious public safety issue," Morgan says. "Somebody cuts these cables down and it wipes out people's life line to emergency services."
"It's frustrating," Eggert says. "I'd rather pay them 50 bucks or something. I'll buy the copper, you know?"
Oklahoma City Police say when they recover copper lines, there's no way to tell which company owns them.
AT&T is offering a $1,000 reward for anyone who calls them with information leading to an arrest.