TEL AVIV // A mysterious arrest carried out recently by Israel’s security services has renewed condemnation from human rights groups about the country’s treatment of prisoners and its possible infringement of press freedoms. A report last week on the website of Israel’s biggest newspaper, Yediot Ahronot, said that a so-called “Mr X” is being held in complete seclusion at the maximum-security Ayalon prison, and his identity is being kept so closely under wraps that it is not even known to his prison guards or fellow inmates. The report cited an unidentified official at Israel’s penitentiary service as saying: “I don’t...