If you pass around Office documents (or many other types of files, including even digital camera files), make sure they’re clean of metadata before you send them out. FCW has an article out today which discusses this very issue:
A new front line of national and corporate security is emerging, and some of the most common document applications, including Microsoft Word documents and PDFs, are putting people on it without their knowledge. In the past several years, federal agencies and private-sector companies have released documents on the Internet that they thought did not contain sensitive content, but they actually did. That has led to embarrassment, scandals, firings and national security breaches when unintended readers discovered the hidden data.
The article discusses tools such as the free Remove Hidden Data tool, something useful to have in your arsenal.