The impact of such organizations goes from rigging construction contracts, for instance by imposing their affiliates' construction materials under the threat of burning the construction site, to controlling legal and illegal activities, such as the transport of toxic waste (which they just bury somewhere around Naples) [2].
More recently, members of both major parties have been caught asking votes controlled by the various mafias in exchange for favors. [3]
[1] http://www.spiegel.de/international/germany/the-vendetta-of-...
[2] https://en.wikipedia.org/wiki/Triangle_of_death_(Italy)
[3] http://napoli.fanpage.it/napoli-perquisizione-al-comitato-el... (sorry, couldn't find it in English)
I live in the densest part of a little English town. We have hardly any garden; our house is three storeys high, narrow and terraced. But it isn't claustrophobic. We can go to the town park/playing field, or the water meadow in the valley, or the walk through the grounds of the big house, or half a dozen other places. Yet the town is still compact and walkable, because this open space is shared between everyone, not walled off.
I love Mediterranean cities like Florence or Barcelona. They are great places to live and to raise your kids/family.