I came across this article that shows what can happen when you don’t get it all right. To quote…

The Los Angeles Police Department is battling a virtual crime wave in downtown L.A. caused by an Internet map coding error.

If the department’s online crime map is to be believed, one might thing that a downtown location just a block from the LAPD’s new headquarters is the most crime-ridden place in the city. In the past six months, that location experienced 1,380 crimes–4 percent of all crimes mapped–or roughly eight a day.

The crimes were real, but a coding error with the system’s geocoding–the process of converting addresses into map points–caused the crimes to be represented at a default location, according to a report Sunday in the Los Angeles Times. The mistake caused many crimes to be mapped miles away from their actual locations, causing false trends to be reported while masking real ones, according to the report.

You can read the full story here