Baby monitors offer parents comfort in knowing their children are safe in their cribs. But what one Ohio family experienced with their unit was so terrifying it could lead you to rethink your own wireless security.

Heather and Adam Schreck were in for a surprise earlier this month when they say they awoke in the middle of the night to a hacker’s voice coming from their 10-month-old daughter’s monitor.

“All of a sudden, I heard what sounded like a man’s voice but I was asleep so I wasn’t sure,” Heather Schreck told WXIX-TV.