Rights activists and protesters paraded through Cairo’s streets on Friday bearing the coffin of a young man they said had been tortured to death in a maximum security prison, calling his treatment evidence that abuses are continuing at the hands of security forces more than nine months after Egypt’s revolution. Essam Atta, 24, was killed Thursday after he was caught with a cellphone, relatives said. They said one of his cellmates had told them guards inserted hoses into Atta’s mouth and anus and forced in water and soap, causing vomiting and bleeding. Protesters likened the alleged incident to the abuses,...