Others have written about having users dispute the charge after the funding was complete and wrecking the goal.
Kickstarter is interesting in some ways, but it is a bad deal for a great many kinds of projects. "Send a satellite to space" great for kickstarter. "We are knocking off this product know one knew was already on amazon" great for kickstarter. But most products would do better selling on Amazon using a "This product will be released on X Date" because the commissions are lower, and if you are only doing $25k for a tangible thing, you can probably get the $15k loan to do it for a lot less, and you will still know how many units you sold before you have to deliver them.
If Kickstarter is going to take such a large percentage they need to do more to prevent this kind of thing from happening.