Take a screenshot?

[Revolucas]

lol. Are you trying to make some sort of surveillance mod? You are looking at some hard coding just to do something so simplistic. The easiest way is probably to teleport yourself to each player and take a screenshot. Which is unreliable and probably stupid, lol. Won't you need client hooks to get the current frame of the minecraft window? Maybe some way to get a clientside mod to work together with a created MCServer plugin to accomplish your goal.