Keylogging - Perhaps the most dangerous method of ID theft used online. It works by installing software on your PC which records every keystroke made on the computer, including your log-in, address and credit card details. This type of software is typically spread through dodgy downloads.
Phishing - Setting up a plausible looking website which claim to be an online business is a favourite technique used by fraudsters. Visitors are encouraged to input personal information, usually after receiving an email requesting they confirm log-in details or check the status of an order. Such emails are sent out to millions of addresses and usually contain warnings that action must be taken immediately in order to frighten the recipient into acting without thinking.
Web hosting companies often shut these websites down very quickly but in the window of opportunity between detection and action they can harvest thousands of account details. Online banks have been targetted as have eBay and PayPal.
Pharming - Even harder to detect, this type of fraud involves criminals using computer security holes to reprogram computers that allocate the addresses for all web pages so even if you key in the correct web address, your web browser may be directed to a bogus site. The only way to foil this is to have adquate layers of security to keep your PC and your ID safe.
Useful sources of help in case you do suffer online ID theft.