I may have missed this, but I was just watching Season 2, episode 5 where Mr. Eko gives Locke the film he found that was edited out of the 'training video' for the hatch. They put it back in and watch it and the Dharma guy (mental block on name, Candle?) says NOT to use the computers for communication, the only function is to enter the numbers. If you use it for communication, it could cause another Incident.
Anyone have clarification on this for me? Or am I being stupid and it is something obvious that has been explained. If so, deepest apologies.