We had a lot of questions for the condo developer Core Development Group after reading they were planning to buy a billion dollars' worth of single family homes in Canada, and turn them into rentals. We were going to put those questions to Core directly. Then they cancelled our interview.

So today, Leilani Farha, former United Nations special rapporteur on housing and global director of the housing advocacy group The Shift on what happens when big money gets into residential home rentals.