I am a realtor and sit on my state's realtor association legislative steering committee, which this year sough to work with legislators on a bill that would limit mass corporate control over housing units... it's surprisingly more complicated than it first appears, and an area where realtors take a view that might be contrary to consumer expectations - we generally like the idea of limitations on corporate ownership, as it in theory creates the greatest opportunity for individual homeownership...

Anyway, some of the scenarios we ran into are things like the 2008 mortgage crisis - what happens if you end up in a market where there is a lot of inventory that no one can afford to hold? In my market, it's starting to look like a lot of builders (read: corporations) built too many houses either that weren't what consumers wanted or demand has shrunk (it is a town with a lot of federal jobs that are evaporating at the moment...). So can a builder hold that inventory indefinitely (assuming they can afford that) as a corporation? Likewise, people often don't want to hear this, but landlords do create efficiencies in the market - there are people out there that either don't want to own a home or can't qualify for a mortgage, and a landlord makes it possible to provide housing for those people as a kind of intermediary. We can argue over what it takes to qualify for a mortgage, but that's really a separate issue. We of course get into the issue of vacation homes or even situations like can I as an individual own a place for my business and a home - after all, they are both real estate, so how tight can we make these rules around ownership? Point being - the basic idea is sound, and some states like CA apparently already have laws on the books, but it's a more complicated matter than just one person == one house.