Sorry, but I have to throw my two cents in here. This forum caught my eye since I am studying digital forensics. Basically, I wanted to say that sometimes it is easy to trace a virus back to the origin but most the time it is not. You typically have a scale of mal-ware creators out there. This scale ranges from newbies to experts. Now, if it is a newbie, then it will be a piece of cake because they will probably forget to hide headers. Usually, these are kids and they might create something that infects a computer, but doesn't do much else. On the other hand, you can have a pro that will basically bring down the house, and they may not ever get caught. The FBI catches people who are careless. A hacker will think that what they have done is so funny that they need to boast about their work. That is when they get caught. People turn them into the authorities. Granted, there are ways to trace it back to origin (if there wasn't, I would be out of a job), but it is not always so easy.
As far as Casey's computer networking skills, there should be some incriminating finds if she did anything. This girl was posting on Myspace and Facebook like nothing happened. If she knew anything about computer forensics, then she would have stayed away from the computer or destroyed the harddrive; that is, if she searched for anything that is telling about the case. However, if she has other parties involved (ie JP), then there might not be much info there. I did some research on JP (Ricardo M's roommate). Apparently, he is a computer science major at UCF. I believe it said that he was in his last year. Just so you know, I also attend this school, and used to major in CS and am full aware that you have to know your stuff to get through that program. UCF offers a very intensive Computer Science program, and most students will fail out or drop out before their junior year. Not to say that kid is actually involved with Caylee's disappearance, but if he is, then he probably guided her in what to do on a computer while her child is missing. All in all, I am more curious as to what is on TonE's computer (my guess is that it is probably a Mac since he goes to Full Sail). She was spending her days there while Caylee was missing, and he was allowing her to use his computer...