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: 0) by Anonymous Coward on Saturday November 26 2016, @11:42PM
Don't mistake, I don't use reddit except for time wasting, I don't have an account or participate in the discussions. Doesn't mean I'm unable to see through your veil of hate and stupidity. I advocate freedom of speech everywhere, whereas you simply spread hate and anger with the occasional good point.