Personal jurisdiction is when someone has enough contacts with a state to make having the lawsuit in that state fair. So you can be sued for causing a traffic accident in a state while only traveling through a state. But you shouldn't be sued in a state that you have never visited and the conduct at the heart of the lawsuit is unrelated to your conduct in the state. Example: someone tries to sue you for defamation in Oklahoma (because that's where they live) for a comment you posted on Lemmy. Unless you live, work, or have property in Oklahoma, it wouldn't be fair to make you travel all the way to Oklahoma to defend a lawsuit.