We don't care at our company. That said, I hired our IT guy and told him we don't care about this
We have some sensitive code, but nobody here is posting full codebases to Dropbox or whatever (incidentally, I hate Dropbox). We have a github for all of our open source stuff and internal cvs for the rest.
As mentioned above, the only safe way to handle this is to run the app on an intranet accessible from within the firewall. This - of course - brings a lot of obstacles and frustrations, like needing VPN just to get your code off of a machine.
Version control apps like SVN also allow authentication/user based rights, so you could essentially have Everynote/Dropbox functionality on a company machine with password requirements. Actually, it would be way less obnoxious than a Dropbox-like integration.