Statistics on DNS censorship, hijacking, and surveillance?

[JeremyRand]

dot-bit/index.md states:

The problem is that these DNS servers are controlled by governments and large corporations, and could abuse their power to censor, hijack, or spy on your Internet usage. This happens on a regular basis across the world, including in countries like China as well as in countries like the United States.

Are there any statistics (or even reasonably representative anecdotes) we could cite for these claims?