For reading someone’s messages, a person must seek their permission and do it with their knowledge. Otherwise, respect their privacy. Reading someone’s messages is an ethical crime; even if they’re your spouse, it doesn’t give you permission to read their messages, emails, or listen to their phone calls. If there is a suspicion of any kind, it should be openly discussed as spying can result in the relationship getting even messier.
By reading someone’s messages, a person not only commits an ethical crime, but also a crime in real sense. A person’s messages can only be available to law enforcement agencies, a prosecutor, or a Grand Jury, under certain circumstances, in a printed layout form. Someone else trying to hack into this information, in anyway, is a violation of the Stored Communications Act, Title 18 USC 2701. The act pertains to unlawful access to stored communications. This can lead to a fine and up to five years of imprisonment or both.