By going to Account Settings and clicking "Account Security," users can now opt into receiving notifications (via email and/or SMS) whenever that user name and password is used to login to Facebook from a new device. Most users probably access the site from just a few devices--home computers, work computers, school computers, and/or mobile devices--so this could prove to be a powerful monitoring system for user accounts.
In addition, if Facebook ever notices anything particularly unusual, like a login from a strange device or simultaneous logins from distant locations, it will send the user through a flow of secure verification questions that we all are now very used to, like "Where were you born?" or "Who was your first kiss?"
As Facebook itself points out, security on the site is already fairly advanced and seamless:
"We've always devoted significant time and effort to security," writes Facebook software engineer Lev Popov. "We've built technical systems that operate behind the scenes to quickly detect and block suspicious behavior, delete phony posts and messages, and return compromised accounts to their rightful owners. Most of these systems are invisible to the average person who uses Facebook."
Nevertheless, privacy and security advocates still barrage the 400+ million member social site with complaints constantly, some of them well-founded. For example, in response to the news that Facebook would be sharing private user data with third-party sites for easier integration between sites, four Democratic US senators sent an open letter to Facebook founder and CEO Mark Zuckerberg, deploring the changes.
