Common meaning:

Confinement area for those who have been convicted of serious crimes.

Hidden meaning of the Equity religion: 

Evidence that the Western system is based on slavery.

Discussion:

The Equityists believe that all of Western society is based on oppression and slavery. Every institution (education, law, medical, military, government, etc..) is, at its core, designed to keep people in chains. 

The idea that all of Western society is oppressive can be traced back to Rousseau. His ideas led directly to the formation of the Equity religion and it still follows them.

Some Equity leaders believe that the best way to find out what the West is really like is by examining its prisons. Given what they find in these prisons, they determine that all of Western society is based on slavery.

It is true that prisons in the West are hard places to live and cause suffering for those who have been incarcerated, but they are not institutions of slavery.

Western societies did not create slavery, they got rid of it.