That's really a wierd situation we have here !
Paypal accepts paying for $LL (dollars linden) or for game-currency and such, tho buying crypto-currencies is against their ToS...
Btw, it seems quite do-able to buy $LL with PP then exchance $LL => BTC or LTC, therefore it won't be possible to charge-back on paypal.
Going further, nothing forbid IFC or other coins to put a "donation" with paypal while, donating would be rewarded by coins. Except trusting the donations' rewarder
Anyone ever tried contacting paypal to know what they think on the subject ?