In the spirit of the fact that a few of these book suggestions have been made available online for free, I feel obligated to point out that Cory Doctorow has chosen to make both Little Brother and Homeland (the sequel to Little Brother, mentioned by another commenter) available in a few different formats on his website. [1] [2]

[1] https://craphound.com/littlebrother/download/

[2] https://craphound.com/homeland/download/

The sequel, Homeland, is also pretty great.

This is truly an amazing read. I also enjoyed this book immensely. It is required reading for my teenage children.