Symantec is warning Internet users about spam campaigns that leverage Diwali, the five-day Hindu festival thats also known as Deepavali or the festival of lights. The spam messages spotted landing in inboxes advertise all sorts of products that can be offered as gifts. If users click on the links from these promotional emails, theyre taken to an online store. Experts advise users to refrain from making purchases from untrusted websites beca…