Wiretapping is a process whereby a third party listens in on a conversation between two people, for the purpose of spying. In the United States, wiretapping is a breach of privacy and illegal unless the wiretapper is a warrant-carrying member of law enforcement. The terminology originates from the old days, when eavesdroppers actually siphoned electric current from a phone line and processed it into speech patterns. Nowadays, there are a variety of other methods to get the job done. If you happen to work for the CIA or another authorized law enforcement agency, a court-ordered warrant is all you need to ask the relevant telephone company to send you recordings of calls to or from a particular phone number.
Illegal wiretapping requires directly tapping into the relevant line using an induction coil to pick up the signal, or planting a covert recording device or “bug” to monitor the target. Because it is extremely difficult to single out a specific caller when the phone line starts merging with lines of other callers, the line must be tapped into close to the house or apartment of the person to be monitored. A good induction coil can be placed next to a line and measure the signal without perturbing it whatsoever. Less skilled attempts to tap the line result in obvious cracking or popping noises as a result of electromagnetic interference reaching the line. The downside of this approach is that it also requires an external recorder, such as a tape recorder, which can be big, noisy, and power-hungry.
Electronic bugs are perhaps the most effective way of wiretapping, and can use power directly from the phone line to transmit a radio signal to a distance of several kilometers. Improvements in miniaturization technology allow bugs to be very small and efficient. To avoid wiretapping attempts almost entirely, one can simply use voice-over-Internet-Protocol (VOIP) technology, which sends voice files as a series of packets over the Internet. Intercepting this type of communications requires an entirely different type of expertise than conventional wiretapping.
After the 9/11 attacks, President Bush authorized the National Security Agency (NSA) to perform wiretapping on thousands of United States citizens suspected of communicating with terrorists overseas, without a warrant. This led to all sorts of political trouble, with many legal experts claiming the President broke the law and violated the Constitution, an allegation the administration denies. In any case, Bush’s wiretapping probably contributed to the drop of his public approval rating to record lows.
