Switchblades are legal in certain states(california being one) as long as the blade is less than 2 inches long. Haven't read anything in the various Knife publications/online that has changed that ruling on blade length. Police and certain military can own switchblades, called automatics these days, and the ones you see advertised are usually aimed at those folks. Most ads carry that disclaimer if you read the fine print. Check with your local state laws online to make sure, though.