Overheard conversations: When heightened mobile security fails to protect

Overheard conversations: When heightened mobile security fails to protect

Summary: You can encrypt, use multi-factor authentication, connect via VPN, have anti-malware software and still give away your identity by making a fundamental mistake when using your mobile phone: Talking too loud.

TOPICS: Security, Mobility

You've heard them at restaurants, sports events and possibly in washrooms — those people who talk too loud on their mobile phones. You thought they were just rude or unaware of the existence of other people, but what they are really guilty of is giving thieves within earshot free access to private information. It's amazing how much information is leaked through this method. No matter how much security you place on someone's phone or what you do to prevent information theft, you just can't shut people up.

All you have to do is focus in on a conversation at a bookstore, restaurant, mall or really any public setting to find out all about someone's life. For the past few days, I've listened with interest to a few conversations. During the course of these conversations, I've learned all about one woman's quest to extract child support from her baby daddy. I've heard about an older lady's hernia operation in extreme detail. I've listened in on two twenty-something's efforts to "hook up." And I've heard one very interesting discussion of how to steal a cell phone and make it your own with the help of a cellular provider (I'm planning to do my own investigative report on that one in the next few weeks — lucky you).

 The funniest conversation I overheard was a man, obviously talking to his wife, who proceeds to give his wife, in a very frustrated tone, his Social Security number and a credit card number, including the three-digit security code from the back of the card. Yes, over the phone, in a bookstore. He had to repeat the numbers a couple of times so that she, who was probably repeating them on the other end of the phone, could make a purchase. I guess he thought his little talk was private since he was sort of off to himself, facing away from everyone.

It didn't matter. I was behind him, pretending to look at the clearance items on a nearby table. He didn't even notice me as he walked by in a huff, nor did he think that I heard every word he said and could have written it down or recorded it. Alas, I could have had a new Nook (or a host of other things) that day, but I didn't partake of his folly.

Instead, I laughed knowing that I now had enough fodder for this post. I was just in the right place at the right time with him. I didn't seek him out like I did the others mentioned earlier. As far as I know, I was the only one listening to him, but there's a possibility that he'll find some unrecognized charges on his next credit card bill thanks to his carelessness.

We all believe that our conversations are secure from eavesdroppers, but we're wrong. It's kind of funny what you and I take for granted. For example, I wasn't doing anything illegal by overhearing his conversation. I wasn't even trying to hear it. I think we assume that our faces are protected by law from camera flashes, our conversations are protected by the First Amendment and our personal information that we spew out at 90 decibels is actually private. It really isn't. And as for the other two, neither are they.

Sure, you can say whatever you want and that is certainly protected by The Constitution, but you can't tell a bystander to "unhear" your 16-digit credit card number that you so freely gave him. Of course, he does commit a crime when he uses it. It's like leaving the keys to your car in its ignition. Your car is yours and no one should touch it but, if you're a reasonable person, you know that when you return from a two-hour mall walk, your car isn't likely to be there. You've basically given it away.

My "common sense" suggestions for mobile phone conversations:

  • Don't conduct private business in public.
  • Never give account numbers over the phone unless you're in a private place, such as your car.
  • Cover your mouth if you have to give out private info in a hurry — I can read lips easily because when people give numbers on a cell phone, they enunciate clearly.
  • Restrooms are not private locations.
  • If you have to talk loud so that the other party can hear you, so can everyone else.
  • Assume that someone is listening and watching. Someone always is.
  • If it's private or personal, it can probably wait.

Don't take chances with your information. Maybe you've been lucky until now but your luck will run out. Eavesdropping is the easiest method of "stealing" your information. And never leave your phone unattended, even for a "minute" because it only takes a few minutes to install malware on your phone. If you don't believe me, a local TV reporter did a story on someone I know who was spied on using her cell phone.

No amount of protection can protect you from yourself. Use encryption, VPNs, anti-malware software, armed guards and a bug zapper but none of it will do a bit of good if you're talking too loud. Some good advice from your childhood: use your inside voice.

Have you overheard any interesting or security compromising conversations in public places? Talk back and let me know.

Topics: Security, Mobility


Kenneth 'Ken' Hess is a full-time Windows and Linux system administrator with 20 years of experience with Mac, Linux, UNIX, and Windows systems in large multi-data center environments.

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  • The world was such a better place...

    ...when people had to go INTO a phone booth to make a telephone call.
    • @IT_Fella

      Agreed. They were also great for changing into my super...never mind. They were great for private phone calls.
  • Drug deal

    On the bus...In central Phoenix. Dickering over the price of pot.
    • @MSUser

      What did they finally settle on? Phoenix is probably a tighter market than here.
  • I hate the spam filter now.

    • thoughts

      Keep your phone protected with a password or PIN, and make sure it's locked whenever it's not in your hands.

      Set up the phone to require a password for installing software.

      Just don't ever leave the phone sitting on a table or desk. Do you really need it there?

      And please ask the webmaster to fix the spam filtering on ZDNet. It's really annoying now.
  • Acoustics

    And don't forget that if you are in a large building with a high domed roof, there may be places where even a whisper can be heard clearly at a matching place somewhere else in the building. This is done deliberately as a science demonstration in some buildings, but even if no such places are marked, the same effect may occur accidentally. If you anticipate that you may be FORCED on some occasion to give your loved one a number over the phone, work out a code with that person, using words for numbers (but not obvious ones), or learn just enough of some obscure dead language such as Sumerian to read off numbers. As for VR systems that invite you to "say or key in" your account number, those companies should tell you to KEY them in unless you are on a ROTARY dial landline phone, instead of implying by their wording that speaking is preferable.

    As a last resort in an emergency, cover your head and the phone with the fluffiest clothing item you can find and speak very close to the phone.
    • technically it would have to be an ellipsoid

      Any wave (or light, if the interior is reflective) emanating from either focus of an ellipsoid will go to the other focus. if you are standing in one and can hear yourself, someone in the other can hear you at the same level. Even a very low whisper.

      Even if it is only elliptical in shape and not a true ellipsoid, the same math still applies but the wave will not be as strong since only a 2 dimensional "slice" of the original wave will be refocused at the other focus.
      • What about the Whispering Gallery in St Pauls Cathedral, London, UK ...

        That's circular and speaking anywhere along the inside of its circumference can be clearly heard at any other point just inside its circumference.
  • Are you Siri-ous?

    This is also good advice for users of voice query systems such as Siri (TM) and others. Asking for directions to "2345 Main Street" on the way to your car could tip off a dishonest bystander where you are going next; perhaps to your bank, where the bystander could be waiting to rob you on the way out!
  • @jallan32

    You're right! I forgot about Siri and Google voice search. People tend to talk louder and enunciate more clearly when using these things which makes it easier for unsavory listeners.
  • Remember the future predictors ...

    who said that the keyboard was obsolete and we'd end up talking to our computers. It's bad enough working in an open plan office and hearing other people's conversations. If everyone talked to their computers, the open plan office would be unworkable from an acoustic viewpoint, let alone the security angle.