Passwords and credit card information for 24 million Zappos.com shoppers were compromised Sunday when hackers broke into the retail website. Industry experts are now urging consumers to take precautions when sending their secure numbers into cyberspace. They say updated virus protection and difficult passwords are key, as is shutting down the computer once making a purchase. Customers are also advised to print out all receipts and confirmation pages, as well as to check all credit card statements. Lastly, it is recommended that people never shop using unsafe wireless networks and never enter sensitive information on an unsecure website.