FaceNiff is an Android app that can be used to hijack sessions on public or private Wi-Fi networks without the need for a computer. It can hack Facebook, Twitter, YouTube, Amazon and Nasza-Klasa (a Polish social network), and more services are coming soon. Thankfully, the app only works on very certain handsets and requires jailbreaking, so it's not going to fall into the hands of too many mischievous Android operators; at least, not yet.

Luckily, it's easy to protect your social networking accounts. Facebook and Twitter allow you to enable secure HTTP sessions as default, so the hackers can't access your accounts and post embarrassing status updates, or worse. On Facebook, simply go to the Account menu, select Account Settings and go to Account Security and tick the “Secure Browsing (https)” box. On Twitter, go to Account Settings and tick the “HTTPS Only” box.