So basically someone could crap on a stock and it is there permanently? That doesn't sound like a good system.
Why not make iboxes strictly for informational purposes - things like what the company does, links to web sites, charts, outstanding shares, financials... and leave the "the ceo is a selfish jerk" stuff for the actual message board?
I have seen several iboxes that are completely worthless because someone went to town painting it with useless baseless opinion - and nobody could modify it based on ibox rules of - if you can't agree, post at the bottom, but never delete someone else's stuff.