PrettCorrect me if I am wrong here, but as I recall the baggy pants thing was actually started by prison inmates as a symbol for (lets just call it willingness or not for attention) (I know...I know... don't be so worried to offend someone; see line 1)
This trend in prisons slowly trickled out, into main stream and the meaning was lost or other non-informed people decided to emulate this "bad" look. It really is an awful trend, although its entertaining to watch some of these guys try to run across the street; with their arms full and pants dragging on the ground, only to trip on their own pants.
Pretty sure that was shown to be an urban legend