(case involves activities of U.S. Border Patrol on private property bordering Mexico and whether agreement by which landowners allowed defendant to install underground motion-sensing devices on property resulted in permanent physical taking rather than a temporary taking; lower court held that such taking was temporary; in early 1990s, plaintiff's predecessors-in-title granted Border Patrol easement along border for patrol purposes; Border Patrol began operating outside easement scope following 9-11-01 and owners sued for taking; while trial court ruled that most claims were time-barred, court ruled that defendant liable for over $3 million in just compensation for temporary physical taking; on appeal, court determined that permanent physical taking occurred because agreement didn't specify removal date; case remanded for recalculation of damages).