[Discuss] Most common (or Most important) privacy leaks

[blu at nedharvey.com (Edward Ned Harvey (blu))]

I see a lot of people and businesses out there, that just don't care about their own privacy.  They email passwords to each other, W2's with salary and social security information, photocopies of drivers' licenses and passports to be used by HR to complete I-9 forms...

As an IT person advising a business to be more responsible, what areas do you advocate securing most urgently?  IT admin credentials?  HR records?  Financial records?  Other stuff?  Simply everything, bar none?

Email is obviously a huge area of insecure information sharing.  Do you also see a lot of people storing information that should be secured in other non-private services like Dropbox, Google Drive, Box, etc?