[quote]Which they can do, but they can't watch everyone at once.[/quote] You, my friend obvously never heard of Massbans. In Halo Reach Bungie banned 15000 Players who exploited at one point. They just looked over their data (which gets tracked in Destiny even more than in Halo) and had proof for cheating. So, yes, they can "watch" everyone at once. No "eyes" needed.