Forgive me if this has been asked before, but I was watching Little Green Men and it occurred to me that Nog was holding that Earth Guidebook with him the moment they went back in time to 1947 and right before they crash-landed and blacked out.
The Federation PADD was clearly in English and contained "a completely interactive program detailing Earth's customs, culture, history and geography."
First off, Nog knows how to READ English but not speak it? (Thanks Jake!)
More importantly, WHAT HAPPENED TO THE GUIDEBOOK!?!?
The humans indicated that they accessed the bridge of the ship, so they must
have found the guidebook just sitting there.
Did somebody pocket it? Do PADDS have a "slide to unlock" password protection feature?
If just leaving a communicator
behind is bad - what happens when you have something like THIS just sitting around?!