To clone a car is easy and as you say my VIN is in the front windscreen. So is my Registration number on the car aswell. Both freely available to anyone that looks at my car. To post my VIN on the internet is no more of a problem than parking it in a public place. How do they get the plates cloned is something that needs to be asked , they cannot get my car and if it is cloned it is not down to me to prove i wasn't there. It is down to the authorities to prove i was....congestion charge,fail to pay for fuel,parking etc.
I have no issues with having my VIN on the internet, it is just a number and any decent SVE will distinguish between a cloned car and the original.
I like the discussion and hope for more discussion on the subject