Watching You:Timeline
From Game Detectives Wiki
Trailheads
On 2016-07-02, the reddit user /u/stvjsmrs (which had existed for at least a month previously) posted to various gaming and ARG-related to subreddits.
/r/ARG and /r/gamedetectives
We have been watching you.
Complete this test to continue a series. You are, for now, alone, but your goal is the same.
i ii ii ii mm m m m G GG U U U RR RR RR II II MM M M
(The /r/gamedetectives post is identical.)
This was solved to be Morse Code, leading to an Imgur image:
