Is it g’neiva to park a car in an empty parking lot which is privately owned and signage shows that it is forbidden to park there. Certainly this would not be moral – my question is if this is zeh neheneh v’zeh lo chaser, or if there are any fiscal obligations here.
Not only is it not moral but it is considered geneiva. We are not allowed to use someone else’s item without their permission, unless we know that that they would permit us to use it. Being that there is a sign up that it isn’t permitted, it would be geneiva. The fact that the person isn’t renting out the parking lot, and the fact that it is zeh nihena will only exempt the person from monetary compensation, but not from the issur itself.
PIschei Choshen 7 ftnt 29, Mamom Yisroel ftnt 134, 140.