it is impossible for people to create bitcoins just like print the money, in my opinion it is one of the things what makes bitcoin a perfect currency
Obviously you cant create Bitcoins yourselves to be used on the Bitcoin blockchain, with Bitcoin public ledger everyne can check its not valid transaction.
But any service where you deposit your real Bitcoin while you get Bitcoin IOU back can create as many Bitcoin IOUs out of thin air for their users as they want, but obviously converting these Bitcoin IOUs back to real Bitcoin which can be used on blockchain can be sometimes very tough task, as the Bitfinex shoved.