Whether it's an iPhone, A Samsung Galaxy SIII, an LG Nexus or some other brand, people seem to want to upgrade their smartphones with the newest version.
But beware: Identity thieves are ready to pounce on old cell phones and uncover their hidden secrets.
All kinds of smart phones can be found for sale on the internet for a broad range of prices.
But that doesn't mean a person should sell to the highest bidder.
Ken Colburn with Data Doctors said a lot of people put their old cell phones up for sale without properly clearing them out of contacts, emails and other personal information.
"If somebody can pick up a device and start acting like you with e-mail, all they have to do is look at the different places you bank, go to the banking website and say, 'I forgot my password,'" Colburn said. "Where do they send re-set passwords? Right to your email. Bam! They got you!"
CBS 5 News looked at just how careless people can be, visiting Craigslist.org to buy a couple of smartphones.
The first was an iPhone 3 for $60.
CBS 5 News had it checked out by a technician and it came back clean.
A Sprint Galaxy was purchased for $40.
An identity thief would have hit the jackpot with this phone.
It was easy to access the previous owner's e-mail account. CBS 5 News found her bank files, doctor's appointments, a link to the owner's Facebook page, names and phone numbers, access to a dating service site and profile and some pornography.
There also was a message that would allow the resetting of the woman's security password.
But the biggest score was the former user's full name and date of birth.
It is just what's needed to open a new credit card account in this former owner's name.
CBS 5 News found the woman, 62-year-old Rusty Howland, in Tucson, called her and told her what was found.
Howland said when she moved to Tucson from Phoenix recently, she left a lot of things in storage, including the phone.
She said she believes she knows who sold the old phone without telling her.
"It's concerning because I trusted this person that they wouldn't do anything this foolish," Howland said. "I didn't think they'd sell the phone without clearing it first, or without my permission."
The best thing you can do to protect your personal info is clear out all the information it contains, Colburn said.
You can clear the contents through the "settings" section of the smartphone.
YouTube also provides step-by-step instructions. Just type the make and model of the phone and "re-set."
"Sell it, donate it, give it to a friend's child - it doesn't matter. If the phone is going to leave your control, you must wipe it out," Colburn said.
CBS 5 News tried to track down the man who sold the smartphones in the first place.
He initially agreed to speak with a reporter, but CBS 5 News has not been able to contact him again.
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