For thieves looking to cash in, the wire is as good as gold.
"Price of copper has been steadily going up. I think it's up around $3 a pound now, so that's made stealing this wire a little more worthwhile endeavor," said Dan Freeman of Caltrans.
Caltrans says they've tried to put security measures in place to make it harder for thieves, but so far it hasn't worked. Every time they have to fix a sign, it's about $22,000.