OMG.. there are DEFINITELY lots of fake Miu Mius out there. Last summer I went to Beijing, and there were lots of fake Miu Miu bags, shoes and wallets.
I'm a miu miu lover, and the bags that I have are of amazing quality. Leather is great, and they even use the same Lampo zippers that Balenciaga uses.
This green bag, i've never seen that done before. It doesn't look like a traditional miu miu bag, but it could just be something from way back.