I found this thread and was curious so I actually looked up the Civ4 BTS EULA.
What I found was quite different from what the people posted above. (Or I think so)
Just for the people looking for the EULA, it's in the Readme.htm file located in the Civ4\BTS folder.
According to clause (b) of the License terms,
(And you agree to the License terms when you are Installing the 'Program', well I vaguely remember that!)
(b) Distribute, lease, license, sell, rent or otherwise transfer or assign this Software, or any copies of this Software, without the express prior written consent of LICENSOR;
Also according to the definition of a 'License'
LICENSE. Subject to this Agreement and its terms and conditions, LICENSOR hereby grants you the non-exclusive, non-transferable, limited right and license to use one copy of the Software for your personal use on a single home or portable computer. The Software is being licensed to you and you hereby acknowledge that no title or ownership in the Software is being transferred or assigned and this Agreement should not be construed as a sale of any rights in the Software. All rights not specifically granted under this Agreement are reserved by LICENSOR and, as applicable, its licensors.
(This is the part where my interpretation comes, so if I am wrong, PLEASE correct me!)
Therefore, the license is only for your personal use. And also cannot be sold [under any conditions], except for the case you get a written consent from the LICENSOR(= TAKE-TWO INTERACTIVE SOFTWARE, INC.).
I find this quite surprising. You are not allowed to sell your games? I never sold mine(thats also surprising as to recall

), but remember buying some second handed.
EDIT// I hope they will actually give consent if actually asked

(I wonder if anyone has attempted to send them a certified mail saying "I want to sell Civ4 to my friend Bill")'
EDIT2// Wait, I found this at the end.
TERMINATION: This Agreement will terminate automatically if you fail to comply with its terms and conditions. In such event, you must destroy all copies of the Software and all of its component parts. You can also end this Agreement by destroying the Software and all copies and reproductions of the Software and deleting and permanently purging the Software from any client server or computer on which it has been installed.
So maybe everyone is right after all. But "you must destroy all copies of the Software and all of its component parts" might include the original. In general thinking of course it does not, but maybe if somebody really want to make the argument in court, that somebody might interpret that to include originals. Now I do not think this is right(ethically), but that somebody's argument could be, "The end user has agreed not to make any copies already, therefore copies actually designates the package itself(and is very clear to me jury!)."
Also, the wording "component parts" is rather ambiguous. It could mean anything. Savefiles, configuration or other files, or maybe also CD, Manual?