I can possibly answer some of this ...   you've seen the grown men in town riding bikes with trailers and they just slowly meander up and down streets.  I've seen them ride up long driveways to take a peeksee at what may be up there.  it's not unusual to see these guys go up the street with a relatively empty trailer and back down and hour or two later with the trailer packed.  or wheeling another bike along side. or carrying a bike tire...or seat.    it's your stolen and missing stuff that they've now got - that also helps support some of these folks.