Well, they are supposed to notify the Department of Public Works/Trash Department for bulk pickup. But I think sometimes people believe that someone else might want their old worn-out stuff so they sit it out on the curb. It happens in my neighborhood all the time (Euclid Street, between 14th & 15th). If the stuff stays there for more than 2 days I just call 311 bulk pickup and they come and get it. Same with abandoned cars, I hate having to do it but if it takes that to get it off my street then I just do it.