Maybe they are renting the house. To find out go to
http://icare.fairfaxcounty.gov/ffxcare/search/commonsearch.aspx?mode=address
type in the street address and you will find the owners name, last sale, etc.
If the name doesn't seem to match an Asian name, they may be renting ... take the name of the owner and find his / her address, send them a letter with pictures and complain ...
Also you can just call the county and they will send someone out to inspect.