Restriction is a measure the membership uses to focus the debate on this site. We are a group of progressive Leftists, but that is all that many of us have in common. We disagree on how the society we envision will work, how best to emancipate the workers and many other issues. We need to debate these things respectfully, amongst ourselves. So we restrict debate about whether we should emancipate the workers at all to the Opposing Ideologies forum.
This is where all right-wingers are sent. This is where anyone who is too disruptive for proper debate is sent. There are other reasons for being restricted to OI of course, but generally it requires behaviour that is deemed in conflict with the membership's vision for this site.
In addition, all forms of social prejudice are considered restrictable offenses. This includes but is not limited to sexism, homophobia, transphobia and racism.