How long is too long?

How long is too long to leave food with mold on in the fridge? Not food, but molding food? I ask because my roommates leave leftovers in the fridge for over a week, and obviously longer since it now has mold specimens on it. Now it takes a bit of time for mold to show itself. I'm curious as to would my roomies eat the food that has been in there between the stages of 5 days to pre-mold. Do they not know that they had Chinese two weeks ago? Are they waiting for a late night craving to finish it off? Just throw the food away! Now there is an abundance of molding leftovers so obviously they don't know who's is who's because there is so much nasty shit in blue and purple tupperware containers. Seriously clean it out man, go to the grocery store, keep it real, keep it healthy. The only green substance allowed in this fridge, vegetables (brocollii, asparugus, green peppers, etc.) mint leaves, lime juice, and green apples. (Mint ice cream goes in the freezer) No green frosty cake, no green beer, no green milk even though one may want it for St. Patty's day. No, it's not natural man. Food colored food is whack and I won't be having any of that. My goal this week is to teach them about mold. Next week is show them the trash dumpster outside our building. Until then keep it clean folks.