Keep your Operating System updated, make sure you run an up-to-date virus scanner, make sure you have the latest version of your web browser and do not enter your social networking passwords on third party sites.
Somehow if you might be affected by this or other scams, simply run an up-to-date virus scanner into full virus scan on your entire system, clear the cookies in your browser (used by XSS attacks) and change your password for the affected account.
PS: dont ever browse ponbon.im, 121.im and 151.im directly on Address Bar. Use Search Engines if you want to look some infos about them.