An overnight camping! Yes, that sounds so interesting. I wonder why putting up a tent will be illegal. Isn't that a common hiking destination that the local authoritirs may already know and allow camping?
How about safety at night? Won't there be any wild animals out there to be scared of?
It's not allowed to camp in the wild in Italy, just at assigned spots, unfortunately.. but I don't think anyone would make a fuss about it :P wolves and bears occasionally roam these parts, but haven't been seen for a while as far as I know..! But better check first if they are around!
For as long as there are no nearby private properties then I guess you are correct, no one will fuss about it. But yes, you better check those wild animals first. Better be safe than sorry. :)