If you halt the program while it is moving files to Quarantine, it will not
have built and saved the index file necessary to remove and rename the files
back to their original names.
I don't know what happens for all classes of files, but for MP3 files, the
files are both moved to quarantine and renamed. You can still play them by
simply renaming the suffix to .mp3.
I don't know of a simple method to get these files back to their original
state. Folks knowledgable about the MP3 format have suggested that the song
titles are encoded in the files, and that there are a number of apps capable
of extracting that information. I've yet to see anyone post clear
information here about how to do a mass-rename of these files, using some
app which pulls out the song title to use for the filename--but this appears
to be at least theoretically possible.
