The locations of the dots do not represent actual addresses. The most detailed geographic identifier in Census Bureau data is the census block. Individual dots are randomly located within a particular census block to match aggregate population totals for that block. As a result, dots in some census blocks may be located in the middle of parks, cemeteries, lakes, or other clearly non-residential areas within that census block. No greater geographic resolution for the 2010 Census data is publicly available (and for good reason).
A more accurate portrayal of the geographic distribution of residents is possible if data is available on the location of parks, buildings, and/or physical addresses. Individual dots could therefore be conditionally placed based on this data.