They will block your access and then you will get stuck in the "you must identify this [some crazy image] of your friend" loop. !#$%#@$^%@!
Yeah because your logging in from a different IP address. Its easy though, they will show you some pictures of your friends and you just verify it!
you can answer a question and get through the loop too. This is only for your protection though and not just shared computers but also when you use your laptop and login from another wifi.
I was impressed that on a recent overseas trip I logged in fine but my teenaged daughter had to verify. I guess if you have "friends" who aren't actually friends then you come unstuck. That's why real facebook users have pages that can be liked by anyone and their friends really are people they know.
But, but, but... what about the Mafia Wars and Farmville players? They have 5000 "friends". I managed to get through the verification. Whew! I set it to allow that IP address and set it to notify me via Text message. Hopefully I'll be able to bring on my new netbook.
Sometimes you just can't avoid logging in from different IP addresses. I've had issues with my account concerning verification and a quick support ticket with the Facebook team has been enough to resolve all my issues.