Just read through the protocol and dire warnings on using espionage v3 with Dropbox.
What if I (definitely) do not want to run espionage on all of the 6 machines (macs and PCs) that sync from my Dropbox account?
If I have to run espionage everywhere, AND, be certain to unlock the folder (namely the whole ^%$# 100GB dropbox) ONLY when it is fully synced and locked on all other machines, then dropbox loses most of its fail-safe, idiot-proof backup utility.
Oh, Mamma, can this really be . . . the end?