Just a brief look through my area and its obvious that even "trained" spotters haven't a clue. Im in Washington Crossing. The numbers are over the place of the reports surrounding me. Hopewell, Ewing, Ewing Twsp NJ, WC, Yardley, Lower Makefield, Morrisville go from 6in to 10.5. Yardley Morrisville Lower Makefield in particular are all the same Zip Code. Ewing-Hopewell too big difference for neighboring towns.Probably not as much as you think. I believe many of those are taken from message boards and not just Joe Schmo on FB - and I know some of the NWS mets are regulars on those boards, so they might know how trustworhty some of the posters are.
I didn't measure myself as I was too busy shoveling, smoking a cigar and enjoying a beer.