ya know, a lot of people will watch the video and get freaked out that this guy can hack so well. but the thing is everything he did was simple and he was only able to do it be cause it was his computer to begin with and the thief was a idiot.
he already had ssh and the remote screen sharing system set up, and most importantly a Dynamic DNS set up loaded. that coupled with a simple knowledge of how a browser stores cookies and when to find the file they were stored in (the second bit being only a google search away and not needing to be previous knowledge). the rest is just application of some simple knowledge of how act and think to get the personal information he needed to send the cops over.
this is a combination of having the forethought to watch the DyDNS record to see if the computer ever came back online and taking advantage of existing tech. it's impressive to see it all come together so nicely, but given the same situation I bet most of us here could do the same.
tl;dr An awesome example of an idiot thief getting owned, and it's a shame that the relatively simple knowledge necessarily to do this is considered arcane wizardry.