A serious security issue was highlighted earlier this year when thousands of people tried to log into a web site thinking it was Facebook. They real issue here is they didn't know how to check if the URL was correct or not. They were lucky this time, it could have been a phishing scam.
You may have heard the horror stories of people getting their identities stolen and their bank accounts raided when surfing the web. This is known as "phishing". This is an introduction to this criminal activity which includes steps you can take to avoid becoming a victim.