Evan Schuman's StorefrontBacktalk

For decades, predictably written TV and movie comedies telegraphed their punchlines. Everyone knew what followed a character saying, “Don’t you grab those plates. You’ll drop them. I’ll do it.” And so it was last week with Google’s news conference to take the wraps off its mobile near field communication (NFC) Google Wallet effort.

In the middle of a live demo of the product, Google Payments VP Osama Bedier told the audience that he was going to use his personal phone and his personal credit card to complete a transaction and that it would all be viewable on the TV screens around the room. He knew the entire event was going to be posted to YouTube, too.

But he also should have known about Murphy’s Law and that he was tempting fate to then tell the audience: “This is my credit card. I’ve obviously blocked out the numbers, but this is my actual credit card. And I’ve pre-entered the information from my credit card into my phone. I’m sorry I can’t show you this screen with the information filled out. I’m a security freak, and this video is probably going to get out to a few places.”

Bedier then placed the screen of the phone on a pad that would beam it to the audience. While the screen displayed “verifying your data” and “your data has been sent to Citi for verification,” it also showed—slightly grayed out but quite readable to the audience—card numbers and expiration data at the top and bottom of the screen. As Bedier saw this on the room’s screens, he quickly grabbed the phone away from the screens’ view, to the amusement and laughter of the audience. Smiling sheepishly, he quipped, “That screen isn’t dark enough.”

Later in the demo, the screen showed more of his credit-card number and the last four digits of his mobile number.

It would be easy enough to dismiss this episode as merely another semi-humorous mishap at a live news conference. (A truly minor glitch: When doing a live demo of what Google has formally dubbed SingleTap, Bedier had to tap twice to get it to work.) But there’s an important lesson here, one that goes beyond the fact that live demos—especially mobile demos, which can experience interference from such a wide range of places—are truly dangerous.

Security has never been primarily about high-end routers and extreme encryption. Those elements are important, but the hallmark of a security person is paranoia.