MINNEAPOLIS - A publicist for Jennifer Lawrence says the actress has contacted authorities after nude photos of her were apparently stolen and posted online.

Naked images purported to be of other female stars were also posted.

Some cyber security experts think hackers may have obtained private celebrity images by exploiting weaknesses in an online image-storing platform known as "the cloud."

"In today's world everything has changed," says Aric Bandy, president of a Minneapolis company called Agosto that develops apps for businesses using Google's cloud.

While cloud technology has huge benefits, Bandy says not all clouds are created equal.

"You absolutely have to look at who it is you're putting your data with. If it's Google, if it's Apple's iCloud, if it's Microsoft," says Bandy. "You can't just trust that since it's the cloud, it's safe."

Another apparent victim is horror movie actress Mary Elizabeth Winstead. She lashed out on Twitter saying, "Knowing those photos were deleted long ago, I can only imagine the creepy effort that went into this."

Even when photos are deleted from a phone, they often live on in the cloud.

"You kind of have to follow a rabbit trail to even figure out what's stored on the cloud," says Bandy.

He advises users to check phone and computer settings to determine exactly what you are backing up on the cloud and whether it needs to be there.