A high-level rat-a-tat would control every back alley of a city; thieves would give him a cut of every theft, or else they'd find violent, animated heaps of trash pursuing them - also a useful deterrent for overly curious lawmen. If troublesome adventurers wander into town, he'd be able to rile the cityfolk into a murderous mob ready to see the heroes' heads on pikes. And if they discovered his schemes, he'd just dodge into the midday mob and vanish without trace.

I don't think I'd like to play this PrC, but it's absolutely brilliant for a nontraditional, Fagin-like, criminal mastermind BBEG.