The "Bill of Rights" has been interpreted by several Supreme Courts to prohibit any branch or agency of any US government, including state, county and city, and any entity receiving funds from any government, such as public school districts, from infringing on the rights of citizens. Basically, the Bill of Rights protects citizens from their government, not each other.

Private entities, such as this forum, may censor at will.

The Bill of Rights applies to the federal government by the express language found throughout the bill of rights.

Certain (most) rights found in the Bill of Rights applies to "state actors" through the incorporation doctrine...the basis of which is the fourteenth amendment.

The Bill of Rights applies to individuals in that it gives individuals certain rights in their relationship with government(s).

Yep. Put much better than by this law school drop out.