The housing protestors are not a mob that has descended on the city from elsewhere, but only represents a tiny fraction of the population, like the G8 protests.

The housing protestors are not a mob that has descended on the city from elsewhere, but only represents a tiny fraction of the population, like the G8 protests. They are local property owners and they all vote in local elections. And then there are the other local property owners who aren't actively involved in the protests but would join them the second they saw their property values drop. Local officials are terrified of this because they can legitimately lose elections over it.