We're way out of topic ;)
So this is only a french thing ?
yes.
Does this means that, as long as your unaware of the fact you should be paying Billag for a broadband access, you're not in a illegal situation ?
no. but this means that some tourist definitely cannot be aware of 26 different local laws (cantons) and will /perhaps/ not get a fine.
some good reference, sorry french only http://www.franceloisirs.ch/affichage/affichagelong.jsp?produitAccedeAvecCat...
Pascal