In sleeping cars that can lock from the inside, yes. I don't want to expose unwilling people to my habits.
Discussion
Well, in the open ones, where you can oversee whole car and see that only other person is a conductor who just left, and anyone coming in will see only top pf your head up until the point he would walk right up to your row. That would be safe call as well.
Where's that route with empty cars? š
In Italy? Not sure, sorry :D
Not in Italy, anywhere in Europe.
Well, I have took some commute trains that are not that not that busy in the odd times. But that is something to czech yourself š