First, it's pretty slimy to intentionally *^%*&^ over another guest that has a valid, paid reservations for the nights that are sold out.

In the US, there are varying laws. In France, you may find your things sitting on the curb when you get back from the Louvre. You may also find yourself with a bill for the RACK rate - the highest possible rate that claim to ever charge for a room. I know rooms in Paris already are expensive, so I can only imagine what this penalty rate is. The Detroit Super Bowl XL rates (I was down the road in an SPG room) may pale in comparison.

Either way, I suspect an American in France trying to pull off a stunt like this won't be very kindly looked upon or treated with empathy.