Atheists should be put in mental hospitals because they are a danger to themselves and others
They are a danger to themselves because unbelievers will be thrown into the lake of fire (Revelation 21:8) and "shall be tormented day and night for ever and ever" (Revelation 20:10). This is not something that a sane person would pursue.
They are a danger to others because they lack a moral compass and that cannot be good for society. Also, the presence of atheists in an area might enrage God which will increase the likelihood of tornadoes and earthquakes.
So I think extreme atheists should be put into prisons or mental hospitals, agnostics may receive outpatient care.