Cheese grease ruins everything! Paper is particularly susceptible to food and beverage contamination. Food and oil can't be separated from paper in the pulping process, so once paper is soiled, it's only good for the trash.

Even worse: Pizza boxes with any oil stains not only cannot be recycled but might introduce food contamination to other items in the recycling system.

Putting such waste in recycling bins is wishcycling. Don't do it!