I've given this some thought before replying, and now here are my thoughts.
I got my first email account in 1995, and the first 3 characters were KR1. That was what 21 years ago? Wow. I really need to get this project moving! OK, so anyway, in todays information-overload world I think it is a natural tendency to cut steps and economize on time especially on the web. The web is an awesome resource for information and shopping. Instead of going to the library or at the least opening an encyclopedia, more answers than ever are a click away. I buy probably 60% of my purchases online. So easy! In the old days for specialty products of course we used "mail order" which is not that different. BUT there is that annoying thing that this information does, too much of it! he people who "just hit reply" are trying to add to the topic or ask a further question, and I truly dont think it is lazy, malicious, or "brainless", or "demented" that they dont take 4x as many seconds to chop the original content down. I try to be in that habit and have screwed up myself when in a hurry. As a regular ordinary list participant, I would MUCH RATHER have duplicate results in my occasional search in the archives, than not have the list. The list rules is something that gets tuned out, even by me (again, that information overload thing and I already read that even if I dont remember it all). So I think the best approach is to single out the most repeat "offenders" with a private reminder, and accept that it will never be airtight, not because anyone is malicious or any of the other bad things, but just human nature. Even with this factored in this list is invaluable and a blessing anyway. My 2 cents.