If you are a Dropbox Pro or Dropbox for Business (paid) customer, did you know you can now use Remote Wipe to remove your Dropbox folder from your computer or device, the next time it goes online? So if your computer is lost or stolen, even if someone can get onto your system, all your Dropbox files will be deleted.
Another new Dropbox Pro and Business feature is that you can set an expiration date for a link you share with someone else. So he/she will only be able to get to that file for a certain period of time, that you can specify.
Unfortunately if you’re using a free Dropbox account, you won’t be able to use these features. This might be a reason to consider upgrading! You now get a massive 1TB of space for $99/year.
Here are the instructions on how to do the remote wipe.