Edits and better integrates the after section

[dbosk]

Edits the intro to the after section (fixes #10): this sets the context and relation to privacy, makes it more clearly related to privacy and surveillance.

Also treats

• TODOs in text (WIP #18),
• general editing (WIP #12),
• there are no particularly technical parts here (WIP #8),
• references are ensured when needed (WIP #5),
• explains in terms of Alice, Bob and Eve (WIP #6),
• uses "demonstration" to refer to our type of protest (WIP #4),
• whether the problem is real (WIP #13) should not be an issue in this section.

[dbosk]

The very last paragraph needs some work still.