Not so much hard, as a dearth of good routes to do so, though it will depend on the plastic exactly what the construction is: Certainly CD cases (polystyrene) dead easy if a waste collector/repositry segregates and sends appropriately. (See CD collection has to go - #19 by Innocent_Bystander). Where I am (NE England) there is a recycle bin emptied fortnightly, accepting all plastics - but not separated, not even from cardboard, glass bottles and metal that go in the same bin, only paper separated. I don’t know if there is a processing station where it is sorted, but if so it would inevitably have to include substantial manual processing as not all would be readily sorted mechanically. (Note to self: something I should look into.) i would put such things through that, but checking with them if, say, CD discs or VHS tapes are acceptable.