Basically, These random users have been "editing" of the studio activity page, there were random messages that say "so and so made edits to the blah blah blah" and IDK what's happening or what is going on here, but this happened about 16 days ago, I've seen it of some studios that have this, They are not invited to any studios and they are adding this. IDK WHO THEY ARE. if this happens to you, idk, try reporting this to ST.
