Hi LW:

I've had the opposite experience...that coincidences happen frequently...and cause 'many a false chase...' until a statistical approach can be brought in to help sift out the 'ground' truth.

In the grapevine quake, maybe looking at cases where there was an Indonesion quake but not an intervening Alaskan M7.9 might provide more insight with regards to any cause and effect going on.

The usenet forecast was in part:
"34.2N118.5+/-1,10/26-10/28(48hrs),Mag2.9-4,...
,&+/-1.2,10/31-11/9,Mag4.1-5.5,...
&+/-2,Mag5.6-6.8 ... Northridge,CA,usa"
The Grapevine M3.5 was at around 34.9N 119.0W. Did your emailer identify what logic he/she was using in their method (It couldn't hurt to ask :). Also, how often do they send one out for that area ?

You are right that there does seem to be many predictions for S. CA...on any given day...some which are generalized and others less so....