The people who are riled up believe that University studies should be performed ethically. They know that IRB's exist to prevent researchers from doing unethical, but legal, things. In this case, they feel the harm caused should have been prevented.
Scraping data silently doesn't cause stress/harm to the participants directly, as they are unaware of any potential threat.
It's not "human experimentation should be banned" its "human experimentation should be heavily scrutinized to prevent harm to participants as much as possible. And definitely never cause harm to unwilling / unwitting participants".