The solution seemed simple when Lyndsey and Sharon Ballinger wanted to move back into their house in Oakland, Calif. — they terminated their tenants’ month-to-month agreement. But there was an expensive complication. The city’s Residential Tenant Relocation Ordinance required them to pay $6,582 to the tenants. After capitulating to what they called the city’s “ransom” demand, the Ballingers sued in federal court, arguing that the relocation fee was an unconstitutional physical taking of their money, and an unconstitutional …