Here is an interesting example of designers/cartographers using their skills to address homelessness. The company is called Cartifact and they have teamed up with the LAPD to map out the data that is collected on street homelessness.

I think it is interesting, but I don't know how useful it is. It clearly communicates the proximity and density of the people but that's about it.

I would love to see it include more data points. Why not include stats on the political climate, the state of government aid, location of shelters, weather information, patrol car routes, or census data for the specific area.

While this sounds like it could get very messy and confusing I think that's where design comes in. Gestalt and other visual design principles help us share all this important knowledge in a way that doesn't overwhelm or intimidate the viewer.

Edward Tufte is all about packing as much information as possible into a small space. He's got some pretty books about it too.