IndieGoGo offers PayPal as an option. Many people prefer it, for various reasons. The funds donated via. credit card directly on IndieGoGo are still available to us.
Maybe you can show Paypal this, demonstrating you are carrying a large share of the risk as well.
It's all risk containment for them. I'm a bit surprised that you would write such a confused blog post about the freeze, isn't it common knowledge that this happens with all Paypal accounts that do not deal in (existing) physical things?
