Tamper-proof seals and radio-frequency ID chips sunk into corks are some of the measures being used in Napa to deter wine fraudsters.
Another anti-fraud measure is the use of inks that are only visible under artificial light, such as UV.
Colgin Cellars is one winery that is using the latest technology to stay one step ahead of counterfeiters, and owner Ann Colgin said: "Our wine is essentially a luxury good, and I do believe that these rare and collectible luxury goods are targets."