The Communications Assistance for Law Enforcement Act was developed in 1994 to assist state and federal law enforcement officials in gathering evidence through the use of pen registers and trace and trap devices. These devices allow officials to determine the origin and destination of incoming and outgoing calls, and the time at which calls begin and terminate. These devices do not determine the location of either caller unless the telephone number is associated with a specific location. In order for law enforcement officials to use pen registers and trace and trap devices effectively it became necessary for them to utilize any telecommunications carrier that might provide communications service to a target suspect. However, before any surveillence can begin a court order or other lawful authorization must be given to the carrier.

Here are the services a telecommunications carrier must provide government officials:

• They must expeditiously enable any government official (who obtains appropriate authorization) to intercept all wire and electronic communications carried out over their medium.
• They must provide all call identifying information. Such as, when and where the call originated and terminated. As well as the phone numbers associated with the communication.
• They shall not include any information that discloses the physical location of the target other than the telephone number.
• They must be able to send intercepted communications and call identifying information to another location chosen by the government official.
• They must provide information on wireless calls that are handed-off or redirected to another service area or provider.
• They must keep secret the fact that the government is intercepting communications.
• They must do all of these things without obstruction and in a manner that protects the privacy of those who are not targets.

CALEA does not limit or restrict the design, configuration, or use of equipment by the telecommunications carriers. However, the communications must be delivered to the officials in usable format unless the communications have been encrypted by a means other than provided by the carrier.

• It does include VOIP because it is concerned with electronic communications, not the means by which they are carried out.
• It does report all wiretaps that end in a given year. Wiretaps
• It does reimburse the carriers for their costs, provided that it is a reasonable assessment.
• It does prohibit the use of any of these features by the carrier themselves.

CALEA permits communications interception only in the investigation of felonies. Most often the highest order of the crimes comitted by a target(s) is listed as drug-related. Currently only 45 states allow the use of communications interception.