Attack Surface

Masha is a brilliant hacker who started off working for the DHS trying to fight homegrown terrorists, then worked for a private company in Iraq tracking Iraqi terrorists and since has worked for more and more dubious but well-paying private corporations setting up spyware on behalf of governments around the world. She also tries to help her friends who are activists fighting dictatorships and white supremacy by improving their digital security. 

The novel is a standalone sequel to Little Brother, but apart from being set in the same world, and Masha knowing characters from Little Brother, there is so little connection that I have logged it as a separate work rather than as part of a series.