Someone using Mark Rage's account is editing whole questions and answers to just contain this picture:
There are many examples, here is just one, but others are easy to find.
What the heck is going on?
Mark has stepped down as a moderator.
The Soup Nazi reference comes from this blog article discussing Stack Overflow (though many parts are still relevant to our site).
To summarize, Mark was unhappy with the direction of moderation (both community and elected moderator). He wanted a lighter touch from moderators, but things haven't been trending in that direction. He left the following message:
Apologies to everyone who voted for me for moderator. I wasn't able to fulfill my promises.
While Mark has not been an active mod for a while, he will still be missed.