Ill put my input for the blog post about "Unusual Linden Dollar Activity" of zeelinden here cause that blog post is closed now.
IF the problem is to make the amount of money spent ingame shown in the home page being more reliable, why not filtering out with the data fetching system transactions like "Object Pays"? That would take out all money given from objects to agents preventing abuses like reported in the blog post, and would make the amount money spend be quite more reliable and credible, since objects cant "spend" money for something, like it happens when someone purchases an item. Even if you go down from 600k US$/day to 500k, its still a lot and its even better cause people know its not a pumped number. Guess anyway that most people have just few "Object Pays" in transaction history, except maybe hardcore campers and gamblers.