Maybe it is Jimmy Buffett. Eventually, whoever did this scam will want to convert their loot into other assets (other currencies, real estate, gold, etc..) so he/she can use it. If it's just some regular Joe, suddenly driving around in his new Maserati might raise a few eyebrows, but would anyone notice Jimmy Buffett with an extra 5 or 6 million?
A lot of people are saying you shouldn't keep anything sensitive in the cloud but having your personal data exposed isn't the only problem here. Dropbox automatically synchronizes to your PC so during this period anyone could have pushed any file out to your PC without your knowledge --maybe substitute an EXE with a virus, or replace your family photos with child porn.
Make a small cube with each wall made of this material so that sound can enter the cube but it can't get out. Next, let it fill up with sound. Take it to the airport, construction sites, concerts, etc...
Then you leave it somewhere with a sign on it that says, "Open Me."