excuse me but... > >> One reason why spam works is that it is so cheap to send 1M messages ... > > There may be a Principle there, about any "cost" imposed upon > >spammers tending to reduce the spam problem... ... > Yes, that is what I had in mind; use any means available to make it > unattractive; persuade them to turn their attention to some other > technology. ... > Something along the lines of 'Know your enemy' comes to mind; get hold of ...the point of the original post was to identify principles. discussions among this engineering-centric community are naturally about methods. the principle i've always followed is that "all communications must be by mutual consent" and i havn't seen anything in this thread to tell me there's some more-universal or more-relevant way to approach it. the messaging protocols we use today do not encode consent in any way. that's why <http://mail-abuse.org/standard.html> is written exactly the way it is. if the protocols could reliably ensure consent, then the definition of abuse could be much more broad. improving authentication sure feels like it's a good way to make consent more likely, but let's not lose sight of the principle, which is consent, while we deal with methods, like authentication. -- Paul Vixie