They probably provided e-mails from Nick Berg saying he was detained. Anyone can do that. Watch:
Hi Little Jeremiah. This is P-Marlowe. I'm sorry I haven't contacted you lately. I've been detained here in Baghdad by the Military police. They will be releasing me tomorrow.
P-Marlowe
now Loftus is saying that Mousauoui BOUGHT Berg's used computer. Most people keep their email password stored inside their mail reader, could that be how he obtained it? Maybe he didn't format the drive before selling it.