Abusing the Trade feature to interrupt, etc

[Bladeglory]

those that are trolled have more power to stop it then they realize. Why not use it?

You answered your own question. If somebody doesn't know that /busy or /blist <t> will help, they essentially can't use it to prevent trade harassment.

I like both methods too, but I think that mpk via trade-spam is more reprehensible than ignorance of features. Punish the trolls, educate the player. Add a third to the mix, too: improve the system where possible. It's our one advantage over the physical world!