Office 365 provides Information Rights Management (IRM) capabilities, which helps users to secure their information by encrypting it and applying an intelligent policy so that only specified internal and/or external people can “act” on the information.
For example, you can allow recipients to edit and print, but restrict them from forwarding to others. This policy is attached to the document, so it is applied no matter where your document lives—whether it’s in transit, on your laptop or a mobile device, or is a USB key—IRM lets you assign policies to email, SharePoint Online libraries, individual Office documents and other file types.
Microsoft will release this capability worldwide in another 4-6 weeks. If you would like to enable IRM in your respective tenant now and provide early feedback, you need to contact your account manager/TAM about it.
Source: Office Blogs