Who are these people?

I'm seeing more and more completely random people around here, people who I don't know at all. I've got no clue where they are coming from or why they are here, but they're freaking me out. See picture and link.

http://zelaron.com/forum/arcade.php?...&module=league

At that link you'll see a lot of people who most likely have never made a single post.

Are these people coming here just to play in the arcade or something?