The key breakthrough by Dr. Pedro Pinto and his team, was to avoid the need to examine every message belonging to every user in a network. How did they do this? Sorry, you'll have to read my Decoded Science article to learn more.
Publicity for my Network Tracing Article
Writing Tip from Tracing Networks
My editor at Decoded Science had suggested this topic and provided contact information. Dr. Pedro Pinto answered my questions quickly, and was very helpful through the brief process.
Sometimes a writing assignment is much more difficult; the source authority might not have time or interest in helping out. However, if you can ask a couple of thoughtful questions, generally they gladly help you publicize their concepts and achievements.
In summary, the writing tip is to ask your source a good question.