Here we have several groups that have put up bins that they clear out very regularly. Salvation Army, Mennonite Centers, Catholic Churches and GoodWill type of stores use these boxes to take in donations, sort-through and then decide if they are to be donated, sold, recycled or thrown-away.
My ex used to work in one of those sorting plants. If the clothing was not good enough to sell, they were cut-up, stuffed into bags and turned into shop-rags - sold to mechanics shops and such. Any metal that wouldn't be good enough to sell ended up in a recycle-bin and then sent on its way to become parts in cars or whatever.
I am sure that those bins you are seeing are similar in nature.