This is a plain-language overview, not legal advice, and rules vary by country and situation. But one principle travels almost everywhere and it is worth saying loudly: tracking another adult without their consent is generally unlawful, and often a serious offence.
The reassuring cases are the consented ones. You can locate your own devices. Families can share locations when everyone opts in. Employers can track company-owned equipment within limits and, in most places, only with clear disclosure. Emergency services can locate a phone that has called for help. The thread running through all of these is agreement, transparency, or a genuine emergency.
The line gets crossed when tracking becomes secret and non-consensual. Installing hidden software on a partner's phone, buying covert location data on a specific person, or using tracking to stalk, intimidate, or control someone can breach privacy law, wiretapping and computer-misuse statutes, and anti-stalking laws all at once. Do not do this. It is harmful, and the fact that a tool exists never makes its misuse acceptable.
If you feel the urge to secretly track someone because you are worried or suspicious, that is a very human feeling, and there are healthier routes: an honest conversation, a mutually agreed sharing app, or, if you fear for someone's safety, contacting the appropriate authorities. If you are worried about being tracked yourself, our guide on protecting your location privacy is a practical place to start.
Where does a prank fit? Comfortably, as long as it stays a prank between friends who laugh at the reveal. Live Sat Tracker never actually locates anyone, stores nothing, and ends every time on gotcha, nothing was tracked. Read what we do and do not do. The joke works precisely because real tracking is serious, and treating it lightly is only funny when no one is actually being watched.