We learned that people will follow authority blindly from the Milgram experiment. Then we learned that people often times don't stand for what's right when they think they have a role to fill from the Stanford prison experiment. For both experiments, the cost wasn't outweighed by the benefits. The experiments did no good and left people with the consequences of the experiment.
The Milgram experiment was considered ethical then, but surely it was close to crossing the line. Now, however, it would be considered unethical due to the deception towards the subjects. The Stanford prison experiment, on the other hand, was not ethical then and wouldn't be considered ethical now. Anything that would lead to psychological harm is unethical and would never be allowed today.
There has been events in the past that exemplifies what these researchers found. In the early 2000's, prank calls were made to managers of restaurants and grocery stores. The caller claimed to be police and convinced the managers to strip search female employees for the "police officer". This happened 70 times throughout the U.S. and is a prime example of blind obedience to