Breaking into abandoned residences is a different issue. It is a common
> problem and a feature of the homeless, drug addicts, and people with
> mental/emotional disorders. They are a neighborhood pest. Eventually the
> neighbors try their best to get the cops to remove them.
>
Depends on who's doing the breaking in, I think. Max Rameau of Miami's Take Back the Land has told me that neighbors are usually quite happy to see their (organized, stable) squatters moving into empty houses. A neighborhood full of vacant buildings is a bad scene, any way you look at it.
You got the "homeless" part right, though. Who else would be looking to squat? (Speculators, in some parts of the country, but that hardly counts as a political activity.)
-- "Hige sceal þe heardra, heorte þe cenre, mod sceal þe mare, þe ure mægen lytlað."