The station has been offering half off gift certificates through its Web site.
But the DA's office says many of them have expiration dates and other restrictions that are not allowed in California.
"This is notification to them that they should stop selling the gift certificates unless they're convinced that the ones they are selling are in accordance with California law," Deputy DA Steve Bolen said.
Attempts to get a comment from KRON4 were unsuccessful.
Gift certificates cannot expire, must allow cash back once they have dwindled in value and in general, must have few strings attached to their usage.