In Chapter 12, what did Malala describe as her "Magic pencil"?

Malala describe the internet and her ability to secretly tell her story as her "magic pencil".

I was writing from the privacy of my bedroom, using a secret identity, but thanks to the Internet, the story of what was happening in Swat was there for the whole world to see. It was as if God had at long last granted my wish for that magic pencil.