I have been watching the latest Atheist Experience show in which Don Baker discusses so-called 'Scamlets,' which are simply patterns of behavior that churches and religious figures engage in to fleece the faithful and gullible. By and large, his talk has been quite good, including references to comic book heroes as possessors of super powers akin to those claimed by faith healers and also a nod to the absence of abuse of supernatural powers from priests and pastors when we see that they are often guilty of other abuses.
That said, I want to mention that this is certainly a problem for the church. And the bigger the church, the more I tend to doubt their sincerity. But in my experience this was not the case. Before I become too distant from my Christian roots, I want to set the record straight, or at least provide an accurate account for some Christians who I believe to be deluded (naturally) but far from dishonest. Maybe I am wrong. Maybe the pastors of the churches I attended were pocketing more money than they should. Maybe the tithes were misused. But my understanding of the tithing process is basically good and has a solid economical basis. The church is a community with a few leaders, either self-appointed or chosen by the community, depending on the denomination. The community elects to put forward a portion of their earnings (in this case, 10%) into the community treasury. From there, the operating costs of the church are paid: minister's salary (he has to live just like everyone else, and I do not advocate a minister living in poverty), other administrative costs, utilities, rent, etc. The leftover funds - ideally a large sum of money, considering 10% of all the members' income - should go to charity. This is essentially the model for communism. Obviously this has been frequently abused by churches, but considering the sheer number of churches in America, it is far more often not abused.
Although it is certainly not my place to complain about where a particular church spends its own funds, the only real problem with church charities is that they are often attached to conditions and come tied to missionaries; instead of simply providing clean drinking water and food for disaster victims, the aid workers hand out bibles and spend their time teaching about Jesus. Again, it's their money and I am not accusing any group of misusing it. Large amounts of aid come from Christian organizations - this is a problem that atheists have. I don't think it is a problem of atheists being selfish and uncaring, but of atheists being individuals and not centrally organized.
The problem with Christian con artists is one that most Christians I know recognize as well. The TV evangelists, who are unfairly tagged as representatives of the faith in general, are the real villains. Maybe the ministers of megachurches qualify for that label as well, although I don't know enough about them to say.
For any church, large or small, for any financial instrument that is cooperatively and collectively fed and used, the key is transparency. If a church can accurately list all of the income from tithes and offerings and accurately list all of the places where the money goes, then there is no risk of a problem. I know that the church I grew up with did just that. I was too young to understand the significance of it, and I have no idea if that is a common practice for most churches or not - it may well be. But if a church member wants to give a full 10% of their income (this is on top of taxes, by the way) to their church, and the church gives a full and accurate representation of where their money goes, then there is no reason to complain. The same church that provided a financial report also decided to build a new church - we had been meeting in a rented storefront - and every week there was a special request for the building fund. Again, although some people may not think that this is the best use of a church's money, it is something that all the people involved wanted and were willing to pay for. Although the eventual building was relatively modest, even if it were lavish and absurdly ornate and hi-tech, there would be no cause to complain. At the end of the day, it was a decision made by a group of sober, like-minded individuals who wanted to spend their money in a certain way.
When the money is asked for - begged for even - there is a problem. Several churches of my childhood would end on a familiar note: "let's pass the collection plate around again as we sing one more verse of Just as I Am." (these churches were not the ones that provided the transparent finances, by the way) This is bad. This is coercion. This is exploiting the weak-minded and sensitive. Humans care - it's a feature of our species. And asking people for money when they are emotionally vulnerable operates on the same principle as happy hour: sell cheap drinks for two hours and then, when your customers are too drunk to make reasonable financial decisions, raise the prices and keep the liquor flowing.