I currently work in an environment where colleagues (irreligious and/or not Jewish) are consuming produce that has shemittah sanctity. They often throw their left over food directly in the bin with other garbage.
Produce that has the sanctity of shevi'it needs to be disposed of separately from normal waste. Are there any actions required on the part of the individual observing this? Can (or should) a person take responsibility for another persons' discarded shemittah produce which has shemittah sanctity?