The need for vigilance committees in San Francisco was obvious. Only two years after gold was discovered at Sutter's Mill in 1848, San Francisco had grown from a sleepy little village with 900 inhabitants to a booming metropolis with more than 200,000 residents. The sudden influx of people overwhelmed the city. Harried law enforcement officials found it nearly impossible to maintain law and order, and chaos was common in the streets, which were lined with saloons and gambling parlors. Attracted by the promise of gold, marauding bands of Australian criminals called "Sydney ducks" robbed and extorted the people of San Francisco with near impunity.