Usually not — not on their personal device. Installing monitoring software, or logging into their phone, email, or messages, can break federal law even in one-party states, and even between married people.
Whose device, whose account
The line that matters is ownership and access. A device you own, or a genuinely shared family account, is a different situation from your spouse's personal, password-protected phone or their private email.
And this is where state law stops being the whole story. Three federal laws sit on top of every state's rules: the Wiretap Act (intercepting messages in transit), the Stored Communications Act (getting into stored messages and email), and the Computer Fraud and Abuse Act (accessing a device or account without authorization). Being married is not authorization.
What to watch out for
Installing stalkerware on someone's phone to capture their texts or calls can be a federal crime. Catching them in the act doesn't make the evidence usable — and it can turn you into the one facing charges or a lawsuit.
A shared iCloud or family plan is a gray area; their personal, locked device is not yours to enter. Guessing a password to "just check" is exactly the access these laws prohibit.
What a licensed investigator can legally do
A licensed private investigator will not hack a phone or plant spyware — it's illegal for anyone, PI or not. What they can do is document behavior through lawful means:
- Surveillance and photography in public places.
- Public-records and open-source research that doesn't require breaking into an account.
See the federal-law overlay for how the Wiretap Act, SCA, and CFAA interact with your state's rules.
Get this handled the right way
Know what's legal where you are, then connect with a licensed investigator who can gather it without crossing a federal line.
Start a caseGeneral legal information only, not legal advice. No attorney–client or investigator relationship is created by reading this.
This guide is general legal information, not legal advice, and laws change. Phone and device monitoring can carry serious criminal and civil penalties under both state and federal law. Confirm the current law for your state at the official code and consult a licensed attorney before accessing anyone's device or accounts.