Don’t e-mail yourself a list of all your passwords and bank account numbers to yourself from work
So my buddy, we’ll call him Bob, runs Data Loss Prevention (DLP) for a big company. DLP is software that limits what you can do with sensitive information, in order to block it from going out of the company. The NSA wasn’t using DLP back when Ed Snowden was working for them; they probably are now.
Sometimes DLP blocks people from sending their own personal information. Doing so is their right–it’s their information–but from a security point of view, I’m really glad DLP kept them from e-mailing their entire life around in plaintext.