CHICAGO (CBS) – Experts were warning west suburban parents this week about something all parents should know about protecting their children from online predators.

Naperville Police Detective Richard Wistocki told parents at Glenbard South High School on Wednesday how predators get children’s confidence by playing online games with them and eventually getting the children to send indecent pictures or videos of themselves. Then the predator engages in sextortion, threatening to post pictures publically unless the children send more pictures, the Naperville Sun reports.

Wistocki said his department deals with one or two times a month of cases of sextortion.

The advice Wistocki had for parents is to “keep their devices out of the bedrooms because bedrooms are for sleeping. There’s no such thing as privacy for children.”

DuPage County State’s Attorney Robert Berlin told parents about laws dealing with cyberstalking and harassing phone calls.

“An actual conversation is not necessary for harassment by telephone,” Berlin said. “It simply could be multiple calls that are just hang-ups or heavy breathing on the other end. It’s important for parents to know these laws are out there when they talk to their children.”