Gordon: And what about escalation?
Batman: Escalation?
Gordon: We start carrying semi-automatics, they buy automatics. We start wearing Kevlar...they buy armor-piercing rounds.
Batman: And?
Gordon: And you're wearing a mask… and jumping off rooftops. Now, take this new guy. Armed robbery, double homicide.
Got a taste for the theatrical. Like you. Leaves a calling card. [hands Batman a Joker playing card]

BioShock uses the latest version of SecureROM technology which includes an authentication technology similar to the activation process that is used in Windows XP and Windows Vista, with a very strict limitation. You may only install the software twice ever. It does appear they do allow you to install the game twice on two machines if you'd like. And I think you can play simultaneously.

I did find out that if you uninstall BioShock, then you are credited back for the installation. That means as long as your hardware doesn't crash, you don't replace any hard drives with out first uninstalling BioShock while connected to the Internet, then you will be able to continue using BioShock.

You are allowed to contact SecureROM in the event you were unlucky and explain to the powers that be why you deserve another chance.

I believe Office 2007 has this "feature" as well, when it comes to handling volume licence users. If you had 10 licenses, as long as you remembered to uninstall before you formatted, and as long as you knew you needed to, you weren't using up licenses. When did we find out, on our eleventh install, after we called Microsoft up to explain there were only like 8 of us using the software.

My biggest complaint is, it takes a long time to install and setup up a machine, soon it will take just as long to uninstall and clean a machine just to be able to safely format it and start over and keep your software.

Over all it's not a real issue that I think will hinder me, but I don't feel that it helps me either. In the past I've waited until a PC was on its last leg before formatting it, now I may be taking a risk on losing my software long term. And I'm not sure one Mulligan is enough.