You've been curious.
You've been wondering.
What are all of these strange text faces.
Well, here's the true story.
xD - Dead Smiling Cyclops
The Cyclopes were not a happy kind. They were always depressed, and they didn't like their life. what am i talking aboutMost of them were dead. An underground fortress houses the rest of the living cyclopes. The Cyclopes eventually found blockland. Though, they still were always depressed. xD is simply a Cyclops' way of stating depression.
This is the most accurate possibility.
:3 - "Help!"
There were legends of a sorcerer that went on a rampage in 1947. It was said that he morphed his victims into cats, stating that they could be lesser than humanity for once. Eventually, the now-cat victims had to think of a solution.
And their best solution was trying to show that they were victims of this sorcerer through online communities.
This is the most accurate possibility.