Why is it OK to read the email of people who work for groups you don't like? Shouldn't the have the same rights as everyone else? If this is acceptable, why is

Why is it OK to read the email of people who work for groups you don't like? Shouldn't the have the same rights as everyone else? If this is acceptable, why is it wrong when the NSA hacks into email accounts of groups they don't like? (And putting "people" in scare quotes as if there's some doubt that they're human? Grow up.)