If you have stuff around the house, you can often part it out and sell the most valuable parts for more than the item as a whole. My local curbs here are virtually a shopping mall/thrift store when you look for value instead of it as refuse, and I wouldn't be able to ignore the opportunity to try to help reduce waste even if there were rules.
Why is this illegal?
RE: 5 More Curb-Salvaged Items Saved & Sold For $470 Revenue (30 Pounds)