RICHMOND, Va. -- Many people sell their old smartphones after they upgrade to the latest device. After all, that old phone still has some life and it's worth a few bucks. So, you erase all your photos and personal information on it, but is the information really gone?

The Better Business Bureau is warning consumers to be careful. They say "erased" doesn't always mean "wiped out" or "gone."

According to a recent Consumer Reports article, the software maker Avast bought 20 Android phones online to see how much personal information was left behind. They found thousands of photographs, including some racy pics with people in various stages of undress. Additionally, they found hundreds of texts, emails, and even a completed loan application.

So how do you protect yourself?

Tom Gallagher, with the Central Virginia Better Business Bureau, says to spend a few extra bucks to be extra safe.

"Make sure that you spend the extra money, take it to a pro. If you want to recycle it and want somebody else to be able to use it, just to make sure that it's cleaned off. You've got to do that. Just because we erase that information, you and I erase it, and we think that it's gone, it's not."

The type of phone you have makes a difference, too. Consumer Reports also has extensive research into how to erase information from Androids, iPhones, iPad, computers, and even game consoles.