This report provides an overview of federal law governing wiretapping and electronic eavesdropping. It also appends citations to state law in the area and contains a bibliography of legal commentary as well as the text of the Electronic Communications Privacy Act (ECPA) and the Foreign Intelligence Surveillance Act (FISA). It is a federal crime to wiretap or to use a machine to capture the communications of others without court approval, unless one of the parties has given their prior consent. It is likewise a federal crime to use or disclose any information acquired by illegal wiretapping or electronic eavesdropping. Violations can result in imprisonment for not more than five years; fines up to $250,000 (up to $500,000 for organizations); in civil liability for damages, attorneys' fees and possibly punitive damages; in disciplinary action against any attorneys involved; and in suppression of any derivative evidence. Congress has created separate but comparable protective schemes for electronic communications (e.g., e-mail) and against the surreptitious use of telephone call monitoring practices such as pen registers and trap and trace devices. Each of these protective schemes comes with a procedural mechanism to afford limited law enforcement access to private communications and communications records under conditions consistent with the dictates of the Fourth Amendment. The government has been given narrowly confined authority to engage in electronic surveillance, conduct physical searches, install and use pen registers and trap and trace devices for law enforcement purposes under the Electronic Communications Privacy Act and for purposes of foreign intelligence gathering under the Foreign Intelligence Surveillance Act. Two FISA provisions, born in the USA PATRIOT Act and dealing with roving wiretaps (section 206) and business records (section 215), are scheduled to expire on December 31, 2009. This report includes a brief summary of the recently expired Protect America Act, P.L. 110-55 and of the Foreign Intelligence Surveillance Act of 1978 Amendments Act of 2008, P.L. 110-261 (H.R. 6304). It is available in an abridged form without footnotes, quotations, or appendices as CRS Report 98-327, Privacy: An Abbreviated Outline of Federal Statutes Governing Wiretapping and Electronic Eavesdropping, by Gina Stevens and Charles Doyle.