Glossary
Personal jurisdiction
A court's authority over a specific defendant, based on the defendant's connection to the state where the court sits. Without personal jurisdiction, a judgment against the defendant is unenforceable.
Personal jurisdiction usually exists if the defendant lives in the state, was served while in the state, or has "minimum contacts" with the state: typically meaning they did business there, caused harm there, or otherwise purposefully directed activity at it.
For online businesses, personal jurisdiction has gotten complicated. Courts have spent decades sorting out when an online presence creates enough contact with a state to allow that state's courts to hear a case. The rules are still evolving.
Unlike subject matter jurisdiction, personal jurisdiction can be waived. If the defendant doesn't object early enough: typically in their first response to the lawsuit: they're treated as having consented.