DENVER - A warning about a new twist on holiday mail theft.
You've probably heard of criminals snatching packages from front porches, or opening Christmas cards looking for cash.
Now, they're stealing mobile devices and leaving only empty boxes behind.
9NEWS followed a newstip and found your holiday packages could be ransacked before reaching their destination.
A lot of people are mailing in their old tablets and other mobile devices to companies in exchange for cash.
Bob Smith tried selling his old iPad, but ended up empty handed.
As holiday packages crisscross the country, more tablets are ending up in the mail.
"There's a lot of activity around mobile devices. Trading them in and reselling and such," Smith said.
Smith bought a new iPad air, so he decided to sell his old iPad and accessories.
He found a company willing to pay $192.
The company sent a box and label and all Smith had to do was pack up his iPad and follow the shipping instructions.
"And then they send you a check. Sounds pretty simple," he said.
Things became complicated when the box arrived at the company, and Smith got an email.
"[They said] there's no iPad in the box and I'm going you've got to be kidding me," Smith said.
Smith filed a theft report with the US Postal Inspection Service, but was told the chances of his iPad being returned are unlikely.
Adding to his frustration, no response from the company, even though he has a receipt proving he mailed the iPad.
Smith hopes others will learn from his misfortune.
"I feel like I should have known better," he said.
As tablets like the iPad explode in popularity, police across the country are seeing a spike in the number of thefts.
These devices contain a lot of personal info, which can also lead to identity theft.
So make sure you clear everything out before mailing your device in and also consider using your own mailing label and getting insurance on your package to cover you if your device is lost or stolen.
(KUSA-TV © 2013 Multimedia Holdings Corporation)