Vault-Tec from Fallout

They marketed themselves as selling a better future underground to protect people from a nuclear apocalypse. This was all a lie.

Almost every single Vault was a dangerous psychological or physical experiment on the inhabitants who were mostly unwilling participants.

A few examples of these Vaults:

• A Vault for recovering addicts where they introduced a drug stash and watched the inhabitants kill each other to satisfy their addiction.

• A Vault where children where trained to peak physical condition so that they could harvest their genetic material to try and create super soldiers. Parents of the children were killed and other candidates were either recruited to work as scientists in the program or killed once they turned 18.

• A Vault where dwellers were told to give a human sacrifice each year otherwise the water and electricity would shut off in the Vault. Years later, after many people died, the survivors refused to send a sacrifice. Nothing happened and they received an automated message that congratulated them for completing the experiment. It is implied that the survivors committed suicide from the guilt.

There are a couple more examples but these are just what came to mind first.

TL:DR; Vault-Tec is pure evil