Is the average ethical review board ethical from an utilitarian standpoint?

Many people argue that Facebook’s study of how the emotions of it’s users changed depending on the emotional content of messages in their facebook feed wouldn’t have been approved by the average ethical review board because facebook didn’t seek informed consent for the experiment.

Is the harm that the average ethical review board prevents less than the harm that they cause by preventing research from happening? Are principles such as requiring informed consent from all research participants justifiable from an utilitarian perspective?