The suit had asked the courts to declare the Terrorist Surveillance Program illegal and unconstitutional. But a judge said the group challenging the wiretap program lacked legal standing.
Humanitarian and peace organizations say their direct interaction with violent or terrorist groups is vital to intervention efforts. The Supreme Court decision Monday means they do it at their peril.
More access by Red Cross workers is likely, but legal analysts are split on whether the prison camp will be less punitive after an Obama-ordered review.
President Obama orders a thorough review of pending terror cases.