Copper thieves are doing on a number on AT&T networks throughout Stockton, Calif.

Since early March, there have been more than 35 thefts of copper wire belonging to AT&T, and 12 documented cases since June 28, The Stockton Record reported this week.

The incidents are cutting off service to thousands of customers; one business customer said his phone, Internet and security-alarm service were down for four days. Two of the thefts also created power outages, dangerous in the mid-summer heat.

Now, AT&T is offering a $5,000 reward for information that results in the arrest and conviction of the thieves.

"AT&T takes this matter very seriously," Robert Ruiz, AT&T’s regional manager for network services, told The Record. "We’re hoping the reward will motivate people in Stockton and in the Central Valley to be alert and to pay close attention to any suspicious people who appear to be working on or trying to cut down AT&T cables."