In Illinois, recording a conversation is a Class 1 felony unless all parties consent; just below the prison time you'd spend for murder
Another example of this disconnect that has recently been brought into sharp focus include laws that police are using to try to prosecute those that digitally record their actions. We already covered how police in some areas can arrest you, if you videotape or photograph them in a public or private setting. Well, in some areas they can arrest you for even recording an audio conversation.
Illinois is one of the states with the toughest laws against audiotaping a conversation between you and another party without their knowledge. The law [text] states that you can face up to 15 years in prison for committing the offense." (more)
Two real life examples... (more) (more)