Some of the most infamous recordings have come from phone call recording where one of the members of a phone call was unaware that a recording device was in use. Interestingly, federal law does allow a conversation to be recorded as long as one member of the call is aware there is a recording occurring. Of course, in some states, this is not the case and it's necessary for all parties to be informed of taping. Those states include Washington, Pennsylvania, New Hampshire, and Nevada. Often mislabeled as "two-party consent" states, the law actually requires all parties to be notified.