Linda Buquet in her Local Search Forum had uncovered a law firm abusing the Google Map business/ local data base by setting up virtual office through UPS boxes and Regus Offices.
Businesses have been using these virtual offices to get approved local listing in Google Maps and other local database for years. Something that is new is: these cases are being outed and caught more frequently these days.
So while doing SEO you should be careful that is might end hurting your main listing.
According to Linda; thi9s can be found easily by the Googlers or Algorithms by looking at patterns, such as “funny looking suit #s like” ste. C-8#149” on their contact us page.
Forum discussion at Local Search Forums & Google Maps Maker Help.