My guess is just a guess but it could be they are just a huge conglomerate where llc's and other entities let them maintain certain aspects of their business structures. For example on a smaller scale here there's a company that started out buying foreclosed homes, rehabbing them then selling and maintaining them to investors. Those investors are all listed at the same address of the company they bought the properties from under different llc's. I learned that from looking into several of the college houses around me back a few years ago when I was having problems with them. The same thing could be going on here, I wouldn't be surprised if they serviced the government entities under contract because, once again, same as here, our city contracts out things like port a pottys for parks as an example, the city may register under them as some named entity (department) as having limited liability if something should happen whereas using an outside contractor and something goes wrong the city is limited in being sued for neglect due to a outside contractor. I can see the same thing within the college rentals, these investors end of letting the realty company take care of their properties at a percentage of rent being made, being a limit liability company listed under them limits the amount they can be sue if say the realty company neglects to keep the properties up, like an example would be failing to keep smoke detector installed and someone dies in a fire, the reality company not the actual owner would be liable. Another example would be looking at the Trump Organization, they don't actually own all those buildings they just maintain them under the Trump name, you'd probably find similar limited liabilities companies listed under each building with different names....for example if their is a store in the building, a restaurant, and the maintenance to those entities are part of the Trump Organizations responsibility, so like looking up the Trump Organization you might find something similar as you find with PM. Massive names down a list. These types of organizations grow over the years, just as with the college houses, it's nothing in comparison to what you are looking at with PM or with what you'd see from the Trump organization but when they first started it was just the people who started the business invested in it, they went on to sell those investments to investors and take care of them for them. Just a thought on what it could actually be.