wire tapping

Definition of wire tapping

Further reading

Telephone tapping (also wire tapping or wiretapping in American English) is the monitoring of telephone and Internet conversations by a third party, often by covert means. The wire tap received its name because, historically, the monitoring connection was an actual electrical tap on the telephone line. Legal wiretapping by a government agency is also called lawful interception. Passive wiretapping monitors or records the traffic, while active wiretapping alters or otherwise affects it.

Telephone tapping is officially strictly controlled in many countries to safeguard privacy; this is the case in all developed democracies. In theory, telephone tapping often needs to be authorized by a court, and is, again in theory, normally only approved when evidence shows it is not possible to detect criminal or subversive activity in less intrusive ways; often the law and regulations require that the crime investigated must be at least of a certain severity. In many jurisdictions however, permission for telephone tapping is easily obtained on a routine basis without further investigation by the court or other entity granting such permission. Illegal or unauthorized telephone tapping is often a criminal offense. However, in certain jurisdictions such as Germany, courts will accept illegally recorded phone calls without the other party's consent as evidence, but the unauthorized telephone tapping will be avenged too.

In the United States, federal agencies may be authorized to engage in wiretaps by the United States Foreign Intelligence Surveillance Court, a court with secret proceedings, in certain circumstances.

Under United States federal law and most state laws, there is nothing illegal about one of the parties to a telephone call recording the conversation, or giving permission for calls to be recorded or permitting their telephone line to be tapped. However the telephone recording laws in most U.S. states require only one party to be aware of the recording, while 12 states require both parties to be aware. It is considered better practice to announce at the beginning of a call that the conversation is being recorded.

Methods

- Official use

The contracts or licenses by which the state controls telephone companies often require that the companies must provide access for tapping lines to law enforcement. In the U.S., telecommunications carriers are required by law to cooperate in the interception of communications for law enforcement purposes under the terms of Communications Assistance for Law Enforcement Act (CALEA).

When telephone exchanges were mechanical, a tap had to be installed by technicians, linking circuits together to route the audio signal from the call. Now that many exchanges have been converted to digital technology tapping is far simpler and can be ordered remotely by computer. Telephone services provided by cable TV companies also use digital switching technology. If the tap is implemented at a digital switch, the switching computer simply copies the digitized bits that represent the phone conversation to a second line and it is impossible to tell whether a line is being tapped. A well-designed tap installed on a phone wire can be difficult to detect. In some instances some law enforcement maybe able to even access a mobile phone's internal microphone even while it isn't actively being used on a phone call (unless the battery is removed). The noises that some people believe to be telephone taps are simply crosstalk created by the coupling of signals from other phone lines.

Data on the calling and called number, time of call and duration, will generally be collected automatically on all calls and stored for later use by the billing department of the phone company. These data can be accessed by security services, often with fewer legal restrictions than for a tap. This information used to be collected using special equipment known as pen registers and trap and trace devices and U.S. law still refers to it under those names. Today, a list of all calls to a specific number can be obtained by sorting billing records. A telephone tap during which only the call information is recorded but not the contents of the phone calls themselves, is called a pen register tap.

For telephone services via digital exchanges, the information collected may additionally include a log of the type of communications media being used (some services treat data and voice communications differently to conserve bandwidth).