In an era when the most esoteric James Bond spy gadget is available to anyone with a credit card, your expectations of privacy are sadly naive.
Take, for example, the telephone sold by Hammacher Schlemmer. The seemingly innocuous princess phone contains a motion detector and a microphone. You can program it so that, when someone wanders into the room, the phone will silently call you and allow you to evesdrop on the conversation.
This and other devices give me the creeps. For example, witness:
The peephole reverser. This lens purports to allow peepers to see into the rooms behind security peepholes. Reporter Erin Andrews discovered to her misfortune how slimeballs can make use of peepholes to invade privacy.
Envelope X-RAY spray that turns paper translucent long enough to read personal info off of a bank statement.
The Computer Snooper, a device the size of a computer plug that, when inserted between the keyboard cable and the port in your computer, will record all your keystrokes without risking detection by security software.
The Bionic Ear Sound Amplifier allows the wearer to hear conversations100 yards away.
Wrist watch digital cameras, right from Q's lab, are actually on the bulky side for covert cameras.
And don't overlook smart phones; am I talking on mine, or taking a video of you?
The sad conclusion? If someone is determined to invade your privacy, the tools available are readily available and almost undetectable. Perhaps the best countering strategy is the one I've adopted; live a boring life.