An onboard motion sensor can trigger an alert on your smartphone, letting you know that whatever you've tagged is on the move, so that bicycle thief won't get far before you're on the trail.

ENGADGET: BluTracker lets you locate your stuff within 2,500 feet, we go hands-on (video)

And remember: The thief doesn't need physical possession of your card to have enough data to do damage to your account.

FORBES: Beware ATM Fraud

To prosecutors, the 26-year-old Swartz was a thief whose aims to make information available didn't excuse the illegal acts he was charged with: breaking into a wiring closet at the Massachusetts Institute of Technology and tapping into its computer network to download millions of paid-access scholarly articles, which he planned to share publicly.

WSJ: MIT to release documents about activist Swartz