You need one of these to make sure you aren't spied upon.
As part of my ongoing security education, I occasionally attend various phreak (hacker) meetings, to keep up with what they are doing. It's also called know thine enemy. At one such meeting about six years ago, one of the group took us out to his car after the meeting and showed us the shotgun mic that he had built from parts. This is a mic that can detect conversations through glass windows at a significant distance.
It was composed of a breadboard circuit, attached to a piece of plywood, a pair of headphones and a very strange looking contraption attached to a shoulder stock and included a tri-pod mount. On the shoulder stock, were mounted three cylindrical objects. The first was a standard rifle scope, for spotting. The second was another rifle scope, with what looked like a black piece of plastic over the primary (front) lens and a small plastic box taped to the eyepiece. The third was a medium power infrared laser (capable of projecting a reflectively detectible beam of coherent light over 2 miles) that he had acquired as salvage. The supposedly black piece of plastic was actually a filter that only allowed the frequency of light put out by the laser, to pass. The plastic box taped to the eyepiece contained the infrared detector and amplifier. There was a speaker laying in the seat next to the breadboard, that would be connected later.
Wires ran everywhere. The breadboard was connected to the car battery, as was the laser. The detector was attached, by a long wire, to the breadboard. The headphones were attached to the breadboard. After a few moments to get the wires untangled and connected. He pointed the laser at a tall building roughly a mile away. It was about 9:00 PM and he explained that he was scanning all of the windows where there were lights on, for sound. After a few moments, he stopped and connected the speaker. He then re-aimed at the selected window and we listened to a Mexican janitor hitting on a maid (without too much success, I might add). Because it was hand held and only braced against the roof of the car, the sound faded in and out, but it would have remained stable if he had it mounted on a tri-pod. He scanned the building for a few more moments and found a radio that had been left on in a darkened office. Then, he swung it around toward a traffic light about a quarter mile away and focused on each of the cars stopped at the light. You could plainly hear the car radios playing or the conversations going on inside the cars. Finally, he swung it around to the glass door of the building that we had just emerged from, about 75 feet away and we could hear the conversation of two people standing just outside the door.
I knew that the government and large detective agencies had such things. But, it blew my socks off to realize that this very effective long-range shotgun mic had been built from salvage, by a kid who was probably no more than 20 years old and whom I wouldn't trust to run my credit card through the Kroger's credit card reader in plain sight, which brings up another point. He proudly told the group that his purpose for building that device, was to get credit card numbers, to use to register AOL accounts. (Hackers often use stolen credit card numbers to register anonymously with AOL and then cancel the AOL account before the trial period expires and the card is actually charged. This makes it much more difficult to trace the hacker.)
Interestingly, I never saw that hacker at any future meetings. Maybe the NSA had him disappear.
As for the key word recognition technology, I refer you to some published research from the University of Southern California. Keep in mind, that if the government allows something like this to be published, it's only because they know that they already have something much better. Here is the QuickTime audio/video presentation of the Berger-Liaw Neural Network Speaker Independent Speech Recognition System. Here is the press release. This study was published in 1999. Today, dependable, high quality speech recognition is not only possible, but in broad use.
As a final note, I would encourage everyone to get and use PGP (Pretty Good Privacy). It is free for individual, non-commercial use and can be found at, http://www.pgp.com/products/freeware.html. With PGP, you publish your public encryption key to a public keyserver, for the world to see. You retain securely, your decryption key. Anyone may encrypt a file or email to you, using your public key, but only you can decrypt that file. The encryption is considered to be industrial strength and if you select the highest level of encryption and a sufficiently long key length, even governments cannot break it without expending extensive time and effort (we're talking months or even years). I personally use it, even for sending trivial messages, whenever the recipient has a published public key. You can also use it to electronically sign documents and that signature is more secure than a document signed in ink, since any change to any part of the signed electronic document will invalidate the signature and it is virtually impossible to forge a PGP signature.
You need one of these to make sure you aren't spied upon.
Back in the 1960s & 70s the KGB was beaming so many microwaves into the US embassy in Moscow that it was considered a health risk. Personnel stationed there on average had white cell counts 40% over normal, and one ambassador died of leukemia.
L