I`m curious though why this would be against the rules. I mean, I have heard of this happening and the person getting in trouble, but what rule would it really be breaking? I suppose you could say it is cheating, that it is "Exploiting a loophole or bug in the system for personal* gain" as quoted from the rules, but what personal gain is it? I suppose it would be easier to spam the market, but if you just wait 15 minutes, you can spam it again anyway...
ah well... doesn`t really matter... I just found the whole thing curious. Of course, now I know how to do it, some knowledgeable players have clued me in. ;) Not really any need for me to use it seeing as I buy minerals and not sell them, but still interesting...