House scalper
Term used by leftist and anti-landlord movement that equates landlordism with ticket scalping (buying up concert tickets and reselling them, which can be banned or illegal). The term intends to point out how many people are against people buying up tickets, but often don't think the same way about a far more important issue, the housing market.
Fifty new houses in the city have just been bought up by that shipping magnate. He's a total house scalper.