DM News reports that California's "Shine the Light" law goes into effect tomorrow, giving direct marketers - both online and offline - the option of either letting customers opt out of databases where information is shared with other companies or allowing customers to receive on demand a list of all the companies with which firms have shared their information. If companies doing business in California decide to go the opt-out route, they must notify all their customers via a letter. If they decide instead to allow for disclosure of data sharing, they have to provide all information that was shared and the names and addresses of those who received it.