When to announce "On your left..."?
Okay, this is a question that's been bugging me for a while and I finally decided to ask -- what's the protocol for announcing "On your left..."? If you're supposed to say it every time you pass someone then there would be rides (like the big charity rides) where I would sound like an auctioneer trying to get around people ("On-yer-left-on-yer-left-on-yer-left-on-yer-left-on-yer-left-on-yer... aww, forget it!"). Once on a large ride I wordlessly passed someone with about 5 feet of space between us and he greeted me with a rather snotty "On YOUR left" or something like that -- for Pete's sake, how much space is enough before you can just ride on by?
The rule of thumb I've been using is that I'll say something if I'm overtaking a lone rider who might not know I'm there (two riders meeting in the middle of nowhere kind of thing) or if I'm passing a rider closely enough that they would have to hold their line or some semblance of a line to keep from swerving into me. Sometimes I'll also announce my presence if someone is lane-hogging and I'm trying to give them a gentle suggestion to move over so that I don't have to ride out into the oncoming lane or pass on the right to get around them. Other than those instances, I really don't see the need to announce -- am I wrong?