Fred,
There is a picture in the NEC handbook on page 182 which shows that the grounding electrode conductor (GEC.) The figure (Exhibit 250.8)shows that the GEC can be connected at the service head, service meter enclosure or in the service equipment. That is as per sec. 250.24(A)(1) However some utilities don't want the GEC attached in their meter enclosure, if you look at 250.68(A) the GEC shall be accessible. Maybe once the meter is locked off, the GEC is no longer accessible.
