Websites often leave personal information and financial data on the hard drive after a transaction. So avoid making holiday purchases from the computers at the public library. Many tech-savvy thieves use viruses and spyware capable of stealing account numbers and passwords right off your computer. Phishing attacks are also on the rise, and growing in sophistication. Phishing, also called "carding," is a high-tech scam that utilizes spam to deceive consumers into disclosing their credit card numbers, bank account information, Social Security numbers, passwords and other sensitive information. The request to provide such data is often motivated by so-called safety measures or the need to update data banks. Some phishing emails threaten a dire consequence if you don't respond.