Subject to enumerated exceptions, it is illegal in the United States to intercept the contents of wire, oral, or electronic communications or to disclose the contents of a communication that one knows to have been illegally intercepted.87 Oral communications are protected whenever the speaker exhibits a reasonable expectation of privacy.88 Wire communications are defined as conversations that travel in whole or in part by wire and are understandable to the human ear.89 Electronic communications are defined as any other transfer of signs, signals, writing, images, sounds, data or intelligence of any nature transmitted in whole or in part by a wire, radio, electromagnetic, photoelectronic, or photo-optical system that affects interstate or foreign commerce.90 Thus, the protection for electronic communications covers faxes and other types of data transfers.
The most frequently used exceptions allow communications to be intercepted by: (1) a law enforcement officer if acting pursuant to a court order;91 (2) any person, if at least one party to the communication gives consent;92 (3) an employer, when acting in the ordinary course of its business;93 and (4) a service provider when the provider is monitoring wire or electronic communications in the normal course of business as a necessary incident to the rendition of service or to protect the rights or property of the provider.94
Individuals now use e-mail as frequently as the telephone, but the distinction between wire and electronic communications retains legal significance. First, voice communications may only be intercepted pursuant to a court order in connection with the suspected commission of certain designated offenses.95 By contrast, electronic communications may be intercepted in connection with the suspected commission of any federal felony.96 Second, electronic communications are not covered by the statutory exclusionary rule, which otherwise prohibits the use of communications unlawfully intercepted in any judicial, legislative, or regulatory proceeding.97
87. 18 U.S.C. § 2511.
88. 18 U.S.C. § 2510(2).
89. 18 U.S.C. § 2510(1).
90. 18 U.S.C. § 2510(12).
91. See 18 U.S.C. § 2516. To obtain such a court order, the government must show that both probable cause and necessity exist. To prove necessity, the government must show that "other investigative procedures have been tried and failed or why [such procedures] reasonably appear to be unlikely to succeed if tried or to be too dangerous." 18 U.S.C. § 2518(c). Even after these requirements are satisfied and the interceptions begin, the government must actively "minimize" interceptions; that is, agents must stop listening (and stop recording) any conversation where criminal activity is not being discussed. Id.
92. See 18 U.S.C. § 2511(c ) & (d). Some states require that all parties to a communication consent to its interception.
93. See 18 U.S.C. § 2510(5)(a).
94. See 18 U.S.C. § 2511(2)(a)(I).
95. See 18 U.S.C. § 2516(1) (providing list of offenses).
96. See 18 U.S.C. § 2516(3).
97. See 18 U.S.C. § 2515 (1994).