According to /u/Spez, Reddit CEO, the reports of messages edited without any user consent or knowledge are correct as he admits to have done it so himself:
Hey Everyone,
Yep. I messed with the "fuck u/spez" comments, replacing "spez" with r/the_donald mods for about an hour. It's been a long week here trying to unwind the r/pizzagate stuff. As much as we try to maintain a good relationship with you all, it does get old getting called a pedophile constantly. As the CEO, I shouldn't play such games, and it's all fixed now. Our community team is pretty pissed at me, so I most assuredly won't do this again.
Fuck u/spez.
The edits were made in a thread linked from the Washington Post which described the recent ban of the /r/pizzagate subreddit which tried to uncover child-molesters and recently moved to voat.co.
(Score: 2) by maxwell demon on Sunday November 27 2016, @03:03PM
Censorship is one thing. Covertly changing someone else's messages is a wholly different thing. That's enough for me to convince me to never post on reddit. I probably wouldn't have anyway, for lack of interest, but now I'll definitely avoid even if I should get in a situation where I might otherwise have considered it.
The Tao of math: The numbers you can count are not the real numbers.