How Can the Charter Protect Freedom of Expression when Digital Platforms Control the Public Square?

Courtesy of the Rouleau Commission I developed a late-onset interest in freedom of peaceful assembly (FPA) and s.2(c) of the Charter. Since then it has been an ongoing concern to me that in more than forty years s.2(c) has not received an authoritative interpretation, much less been considered or discussed in any depth by the Supreme Court of Canada.

Universities have property rights. Are they entitled, as a consequence, to exclude others at will? Are property rights, especially those exercised by public institutions like universities, different from homeowners or shop owners?