Nabila Mango, a therapist and a U.S. citizen who has lived in the country since 1965, had just flown in from Jordan last December when, she said, she was detained at customs and her cellphone was taken from her purse. Her daughter, waiting outside San Francisco International Airport, tried repeatedly to call her during the hour and a half she was questioned. But after her phone was returned, Mango saw that records of her daughter’s calls had been erased. A few months earlier in the same airport, a tech engineer returning from a business trip to London objected when a federal agent asked him to type his password into his laptop computer. ‘This laptop doesn’t belong to me,’ he remembers protesting. ‘It belongs to my company.’ Eventually, he agreed to log on and stood by as the officer copied the Web sites he had visited, said the engineer, a U.S. citizen who spoke on the condition of anonymity for fear of calling attention to himself. Maria Udy, a marketing executive with a global travel management firm in Bethesda, said her company laptop was seized by a federal agent as she was flying from Dulles International Airport to London […]