There are specific laws when it comes to recording telephone sound. While the recording of sound itself is not illegal, the recording of the voice of another person violates that person's expectance of privacy.This expectance of privacy is inherent in the Fourth Amendment of the Constitution.
Recording With Consent
To legally record a conversation the person doing the recording must obtain the consent of all of the individuals involved in most cases. There are a few states with two party consent statutes where all parties involved in the conversation have to give consent. These states are California, Connecticut, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Pennsylvania and Washington. All other states have a one party consent statute which requires only one party to give consent to the recording.
Recording the conversations of other people without consent is considered warrantless surveillance and has severe penalties. This means that if you are not one of the parties involved and you record the conversation either party may take legal action against you. Furthermore, if the conversation takes place across state lines (the parties are in different states) then both state laws are applicable.
Penalties for Recording Without Consent
When there is a situation that involves recording telephone sound, laws provide strict penalties for those who choose to ignore the written statutes. Federal sanctions are listed in United States TITLE 50 CHAPTER 36 SUBCHAPTER I § 1809 which states that warrantless surveillance “is punishable by a fine of not more than $10,000 or imprisonment for not more than five years, or both." This is for any telephone recording that crosses state lines in addition to the applicable state laws. Every state has its own laws regarding both specific exceptions to the warrantless surveillance law and the score and severity of its penalties.
One of the most famous recent cases of recording without consent involved Linda Tripp and her recordings of conversations with Monica Lewinsky. She was indicted in Maryland on criminal charges of illegal wiretapping. Although she wasn't convicted the public backlash that she suffered is a sign that the public feels very strongly about their privacy.
There is an exception to the consent rule when it comes to business calls. Any call that is conducted to or from a business and falls within the everyday workings of the business may be recorded without explicit consent. If the call originates in another state then the company must give the caller a verbal prompt that states that the call may be recorded.
Although most of the laws regarding wiretapping and recording telephone sounds were penned before the advent of cellular phones and video tape recorders they still apply. Wireless transmissions are covered just the same as the land line variety, so intercepting them by means of a scanner is against the law just the same as physically tapping into their landline. Video recorders that also record audio are subject to the recording telephone sound laws. Any conversation that would not be able to be overheard in the natural progression of everyday activities is subject to these laws.