Estimates show that 40% home security cameras are hacked.

Security cameras are supposed to be an added level of protection, but for some families their Ring cameras have done more harm than good.

Last week an 8-year-old Mississippi girl was terrorized in her room.

“I’m your best friend. I’m Santa Claus,” a voice from the Ring camera said.

And this week, a family in Florida was berated with racial slurs.

Hackers also have victimized other Ring customers in the U.S. So how does something like this happen?

Mostly through operator error, said Roman Yampolskiy, an associate professor of computer science and engineering at the University of Louisville.

“The system itself is pretty secure, but if you set it up incorrectly, your password is too weak, the local Wi-Fi is not secured properly, then it becomes possible for pretty much anyone to get access,” he said.

For example, Yampolskiy recommends consumers refrain from using their children’s or pets’ names for passwords.

“Ideally have a piece of software generate them for you,” he said.

You also should never use the same username and password for multiple accounts, he said, and you should choose complicated and unique passwords for each account.

“For example, I don’t know my passwords, I can’t divulge them if you torture me. They are random strings generated by a program,” Yampolskiy said.

The Ring company said in a statement, “Our security team has investigated this incident and we have no evidence of an unauthorized intrusion or compromise of Ring’s systems or network.”

If you have a Ring account, the company suggests you use two-factor authentication where you’ll receive a unique code via text message when someone tries to log into your account.

Yampolskiy said that if you do install it properly, Ring is pretty safe.

“It still provides a beneficial service: having this ability to see who’s at your door stops physical hacking of your house,” Yampolskiy said.