(CBS) — How many times have you traded in your cell phone or sold one?  Were you sure all your sensitive information was wiped away?

CBS 2’s Dorothy Tucker bought more than 100 used phones and found plenty on them.

Consumers search, send and store too much personal information on their cell phones.

If you upgrade, recycle, sell or trash that old phone, your data could still be there. It doesn’t matter what how battered the phone looks.

“It matters what I can pull out of the USB port,” says Jared Sikorski, a forensic investigator with 4Discovery.

Sikorski recovers cell phone data for legitimate reasons, but hackers can get at information, too.

CBS 2 bought several old cell phones at online auction sites for less than $2 each.

The 2 Investigators powered up some of the 155 phones and discovered who owned them, who they called and who kept racy photos.

Then CBS 2 took the phones to 4Discovery where they found addresses, schools, child custody arguments, porn and even prostitution.

Sometimes they were able to recover deleted contacts, which led CBS 2 to family and friends.

CBS 2’s security experts looked at 500 phones and recovered 33,000 videos, 321,000 emails, 478,000 texts and 600,000 photos.

Also, there were 26 credit cards and 36 Social Security Numbers.

“Anyone else could use that information to open up other accounts or access other data,” Sikorski warns.

To make your phone more secure, make sure it’s encrypted.

Newer phones do that automatically, but with older models you have to encrypt them through settings.

Before a phone leaves your hands for good, make sure you erase as much information as possible.

Just smashing a phone won’t work. You have to destroy the small memory chip inside. Shredding it is also an option. That is what CBS 2 will do with the phones it purchased.

Security experts say older phones are easier to hack, especially iPhone 4’s and earlier models and any Android phones running older operating systems.

Dorothy Tucker