How can one take loan with my identity? I mean, banks don't give away loan so easily, I can't really think that someone can do anything with pictures of my ID card, at least I'm unable to do things with it alone.
Depends on your bank and your jurisdiction. Some banks will happily let you open accounts, set up credit cards, take out loans, even take out mortgages, all over the internet. Often a picture of your ID is enough, and if they want more such as tax numbers, recent bills, etc., then these can be often be obtained by an attacker with a copy of your ID/passport/whatever and your other personal details.
Whenever I have to send some personal documents to some company (for setting up a bank account, utility services, amongst others) I always make sure to include a watermark with numerous information (such as which company I'm sending the data to, which data and why). In the event their security is weak and this data is stolen from them, probably no one will be able to open a credit line in my name due to the watermark, and if I ever see those documents floating online I'll know which company was the one responsible for the leak.