YouTube is crushing our national TV product, so let's tax YouTube.
It seems... fine.
But legislators are slow and companies are smart, so likely what would happen is something like: 1. Tax goes in place. 2. YouTube decreases the quality and starts broadcasting in 640x480 VGA. 3. France gets pissed. Forces them to 'distribute content at world standards with a law' 4. YouTube challenges the law in court. 5. The case costs the French more than the revenue provided in the meanwhile.
Or YouTube leaves France.
Who is winning here?