If you are interested there are some articles here on the a2 squared site (they make a scanner, software firewall)
Do some research and arm yourself with the meaning of keylogger, software firewall, hardware firewall, spyware, adware, spybots, viruses, trojans
It is always changing with new ways of getting into your system
http://www.emsisoft.com/en/kb/articles/
Also register your card here,
http://www.mastercard.com/uk/gateway.html
This helps too. When in the process of a transaction it will ask you a random character from a password you created, before it lets you make the final purchase
