They are "infiltrating" the world of gamers because they are looking for recruits like in this movie:
The Last Starfighter: Trailer-park teenager Lance Guest regularly escapes from his humdrum existence by playing the video game Starfighter. His expertise at this recreational endeavor attracts the attention of affable stranger Robert Preston. Before he knows what's happening, Guest is whisked by Preston into the outer reaches of the galaxy! It turns out that the Starfighter game is being played in deadly earnest in outer space, and that Guest is expected to join Preston's Star League, then do battle with the wicked Kodan forces.