I can add to what Nemoy has spoken about.
Absolutely, put a hard limit on the number of units REITs can purchase or own, and block any public funding or benefit that REITs receive. Those should be tied to a no-displacement guarantee. If a REIT wants CMHC funding, then it has to guarantee CMHC that it's not going to displace tenants.
Part of it should be making sure that REITs maintain their units. The tenant conditions we live in are just abysmal. Their profit model relies solely on, basically, putting us in conditions that are not livable.
Taxing REITs.... I think the best way to hit a financial corporation is the bottom line, so a tax of 38% is a great number.