We have detected suspicious activity on your Facebook account and have temporarily suspended your account as a security precaution. It is possible that malicious software was downloaded to your computer or that your password was stolen by a phishing website designed to look like Facebook.
You can regain control of your account by logging into Facebook and following the on-screen instructions.
Please be sure to visit the Facebook Help Center (http://www.facebook.com/help.php) for further information regarding these security issues and let us know if you need assistance.
Facebook Security Team
I didn't open the link in the e-mail as I am cautious it might be a phishing e-mail. There have been many cases reported in news where users lost their bank account money due to phishing e-mail.
I opened a new web browser and logged in to Facebook. It turned out that the e-mail was really sent out by Facebook. My Facebook account was suspended. Following the instruction, I needed to verify myself using my birthday date and also to change to new password.
It crossed into my mind that might be my Facebook account password was stolen. Then, I suspected it might due to my recent usage of ebuddy. In ebuddy, I put in my yahoo mail, msn and facebook log in details in order to use the chatting software. Before I used ebuddy, I never received any security warning from Facebook. At here, I am not finger pointing to ebuddy but this is the only possible root cause I can think of.
Beware of the possible threat, I also go to change my yahoo mail and msn account password.
Maybe some of you also received the same e-mail from Facebook.