CHICAGO (CBS) – There is a widespread and growing danger allowing sexual predators inside your home. Criminals are using web cameras to spy on people.

CBS 2′s Dave Savini spoke with the FBI about this troubling danger and how you can protect yourself and your children.

It is not just criminals doing the spying either.

High school sophomore Blake Robbins was spied on in his bedroom through his laptop. It was a school computer he was using, and it was school officials who did the spying, according to his mother, Holly Robbins.

“I don’t feel that the school has the right to put cameras inside kids’ homes, inside their bedrooms, and spy on children,” she said.

The ability to spy can happen when someone tampers directly with your computer, like a repairman; or by sending a virus allowing them to remotely access your computer.

FBI Special Agent Eric Brelsford said web camera spying is, “extremely prevalent. It’s very widespread and I think it’s just going to continue to grow.”

He said the biggest concern is pedophiles and sexual predators.

“In particular, predators that may be attempting to target children,” said Brelsford, who was not able to discuss any specific investigations.

This type of intrusion is very prevalent in college, Brelsford said.

A form of it is being blamed for the suicide of a Rutgers University student, who was spending time with a man, and was spied on by his roommate.

There are plenty of Internet sites directing people on how to spy; even showing how to disable the web camera light so it appears the camera is off when it is actually on.

Brelsford said victims often do not know they are being watched. They only find out if approached by the offender. So check your web cameras at home, and make sure they are covered or shut down when you’re not using them.

The technology to spy is not necessarily illegal. Parents can use it to monitor their kids. It is how the technology is used that makes it a crime.

Authorities say the simplest way to protect yourself against web cam hackers is to take a post-it note and put it over the camera when you are not using it. You also could unplug your camera, or power down your computer when you are not using it.

In the case of Blake Robbins, he did not know he was being watched until confronted by an assistant principal with pictures of himself in his bedroom.

“She thought I was selling drugs, which it’s completely false,” Blake said.

He was not selling drugs. The pictures were misconstrued. Robbins won a lawsuit against his suburban Philadelphia school district.