Housing as a commodity and stockpiling to force prices upwards.

Spain's mortgage scandal was every bit as bad as our own and as is here stockpiling is not entirely legal and sometimes criminal. 

The concept goes like this:

1. Purchase troubled mortgages at discount
2. Aggressively pursue eviction or re-mortgage at variable schedule
3. Stockpile property & mortgages forcing prices and rents upwards
4. Sell/Rent at substantial profit

We all know the skulduggery that led up to this, now the major "wealth accumulators" are attempting to corner this as a commodity market to reap more profits on the other side of the mortgage scandal. I got to watch a distressed real estate fund setup with exactly this in mind.  Naturally it's quite a bit more complicated than what I just laid out but cut to the bare concepts that sums it up.