Google's ($GOOG) keyword advertising program, AdWords,  has been subject to constant legal challenges for the past decade.  After an initial period of legal uncertainty, AdWords' legal fortunes recently have brightened in the United States and Europe.  Last week, AdWords notched another strong win in court, this time in Australia.  Considering these developments as a whole, Google has effectively gotten a clean legal bill of health for its AdWords service around the globe.  Google's impressive accomplishment also provides a useful cautionary tale about overregulating technological innovations.