Here is an invaluable guide for journalists covering controversial events or activities, or working in countries with media restrictions. You can download for free as an ebook A Guide for the Savvy Journalist in a World of Ever Decreasing Privacy. There is a great deal of useful practical advice on how to protect yourself and sources in a world where digital security can and is breached. The book is supported by Reporters without Borders, a group that knows the dangers that reporters on the ground increasingly face.