Ok almost all of us use Facebook and Facebook will send a mail to your inbox whenever anything happens in you account like Someone comment on your Status, If someone Post Wall to you etc, to keep you update with your account. Facebook also uses its own URL redirect service so that if anyone post any URL on Facebook and if you click on that link then Facebook will use its redirect service to open that page,It URL redirect service may look like this :-
For eg if you put http://www.facebook.com/l/77059;technoarea.in in your address bar then you will be taken to TechnoArea’s homepage,
Now you will ask how Hackers are using it ? Well Hackers first shorten their page URL (which contain malicious things) using any URL shorten service like bit.ly and then add it to Facebook redirect URL and send you a mail Like someone posted wall and to check click on that link, When you look at the link you will see Facebook and click on it but then it will take you to Hackers page and you information will be stolen.
For eg :- http://www.facebook.com/l/77059;goo.gl/40N3
As from above link you cant figure out the page (Its TechnoArea URL).
So beware from such mails and links.