On December 22nd 2014, a Delta Airlines Boeing 737 was damaged by a large container used by DGS cleaning company. The impact tore a hole behind the wing.
The 737 was parked at gate B37 Terminal 4.
DGS (http://deltaglobalaviation.com) offers jobs for aircraft cleaners, skycaps, and ramp agents. I don’t see dumpster driving on their list….