In a most interesting article at The National Interest, Alexander Joffe writes about an archival boon of the so-called "Arab Spring" -- access to the files and archives of deposed dictators. Joffe wonders if we will soon have the ability to cull research from the files of Bashar al-Assad, Qaddafi and others. A lot of these files were destroyed, of course, mostly by the men of the downed despots in an attempt to protect themselves from revenge and future prosecution.
For another example of an archive opened after the fall of a repressive regime, check out the archives of the Stasi, the East German secret police, now opened to the public. (And for fun, here is the scene from the wonderful movie "The Lives of Others," in which the main character receives a whole lot of files in the Stasi archive.)