[quote name='mogamer']Yea, NEVER buy a Source engine game used! But I don't know of any other games that are that bad. I guess if it was like Bioshock and it was already put on the maximum number of PC's you would be screwed. If you did get screwed, you could always look for a crack.[/quote]
Not that it really matters but if you do get a source game used you can send valve pics of the software and box along with the serial # and they will move it to your account.