Since TonyStark is returning I will continue on with the limited crime vein, we could call it territory.  The general idea would be to make the crimes available limited in each city. A table would be nice, so the crime limit would not just be enough to support 75 (just a number) players per city, but the there would be only so  many of each, so even a capo might have to snatch a purse. I dont know if limitng the number would work better or if maybe just limiting the higher level crimes would do, there are potentially thousands of purses. This may create a slight pressure to expand as income flattens out. A number of game features could be used once the pressure starts to peak across all cities, mobsters may try to hit a post office in another city just to make the extra dough. W/S and stealth could all come into play here, creating friction between cities. Depressing drug prices was a good point and could also be used I imagine. We  might see cities with 5 crews of 10 or a crew of 50 and 25 before things get tight. Rank could come into play here, higher ranks could create bigger families and open up higher level crimes for the city. Lots of possible interactions.

That could indeed be interesting. I know I for one am intrigued at the idea of cities being broken down into districts and how that is going to affect the game play we receive. To expand on what your saying about going to other cities to hit their post offices. I don't know how hard this would be to code, but if possible the admins could make it that the more post offices being hit then the more aware the post office staff would be. Thus increasing the chance of a failure if too many people are in one city trying to hit the post office. This would then force people to start using the other crimes available in later ranks rather than them just being used at the lower ranks.