They called them the den of traitors.
The four classes were the following:
gentry and scholars (shi)
peasant farmers (nong)
craftsmen (gong)
shang (merchants)
the top of the hierarchy was occupied by the shi - the gentry.
When a person is declared by Congress to be guilty of a crime, even though the person has not been given a trial is an example of bill of attainder. The right of due process is violated by this specific bill.
In the past, the Bill of Attainder has resulted in the execution of a lot of important figures in history.