Grandalf's point is extremely well taken. It's actually true. Not only that, but regulated companies (in health care and finance) that have a reasonable belief that any of their systems might have had Dropbox on them technically need to audit now.
I point this out not to bag on Dropbox, but as an illustration of how sane some unreasonable-sounding IT policies (like, "you don't get to install random software on your desktop") turn out to be.
† (Or Tarsnap or SpiderOak, for what it's worth.)
