Soft plastics such as those used in plastic shopping bags are not easily recycled and due to be lightweight can get blown around and caught in machinery causing problems for large recycling facilities. The only plastics that are normally accepted curbside are bottles, cans, and jugs with the recycling symbol on them, not soft plastics like bags or hard plastics like old toys or tubs. Yet another reason not to put your plastic bags in the curbside recycling bin is that they can very easily blow out and become litter.