It may or may not be legal to record conversations in the U.S. depending on the state, and depending on whether or not other people consent to being recorded. California has 2-party consent law when it comes to recording conversations. In other words, it's a crime to record a conversation with another person and not tell them: https://www.google.com/search?q=california+conversaion+recor....

(Law enforcement is exempt from this restriction, of course).