123.025 is a metro unicom frequency for helicopters. Only the FAA has control of that frequency, not SysCom. This frequency is used for coordination of multiple aircraft from multiple agencies/organizations, including private, operating/transiting in a metro area. It heavily used in the baltimore metro area, even down toward the maryland suburbs of DC.
As a side note, a fair amount of information is passed across this frequency during breaking news events between news helicopters, and sometimes, even some other agencys. It is amazing the amount of cooperation that happens up in air.
Mike