DANVILLE, Ind. (AP) _ Big Brother is phoning in Hendricks County, and people who drink while serving sentences at home have reason to worry.

The county probation department has a new device that uses a computer and a special phone to monitor up to 50 people to see if they have violated their parole by drinking alcohol.

The home detention system, developed by Digital Products Corp., keeps track of people electronically, registering the whereabouts of their wrist or ankle bracelets with a central computer.

But this computer also makes phone calls, and a sensor built into the receiver analyzes the person's breath. The device can't measure the amount of alcohol consumed, only say whether alcohol is detected.

After calling back twice to verify positive findings, the computer automatically summons a probation officer to the home for a more conventional test.

Probation director R. Todd McCormack acknowledges the technology is invasive, but said ''there is nothing that says I can't be just as aggressive as any private organization out there.''

The program costs about $4,400 a month, but generates twice that in fees paid by the detainees.