Here in Portola Valley we have a email group and a few times a week people bitch about, for example, the white BMW that almost killed them, etc. etc.
No one is listening, people. The dipshits who are driving selfishly don't care about your email scolding.
Likewise, I think appealing to the membership of BARF to lower splitting speed deltas is largely useless, because there are so many irresponsible bikers who aren't debating issues on the forums--they're on the road pissing people off.
That said, discussions on the BARF have had an effect on my splitting speeds. I'm rarely splitting at a 25 mph delta now, and much closer to 15 mph most of the time.