Do you have pdf documnets on your website? If so you need to read this

Well this Register article which informs us that:

"A bug in Microsoft's Internet Explorer browser is causing more than 50 million files stored online to leak potentially sensitive information that could compromise user privacy, a security researcher said.

The documents stored in Adobe's PDF format display the internal disk location where the file is stored, an oversight that can inadvertently expose real-world names and login IDs of users, the operating system being used and other information that is better kept private. The data can then be retrieved using simple web searches.

Google searches such as this one expose almost four million documents residing on users' C drives alone. Combined with searches for other common drives, the technique exposes more than 50 million files that display the local disk path, according to Inferno, a security researcher for a large software company who asked that his real name not be used."