This is a good reason to open it. With an open wifi there is no good case that it was you. With a secured wifi - you simply have to convince an 80year old judge

This is a good reason to open it. With an open wifi there is no good case that it was you. With a secured wifi - you simply have to convince an 80year old judge and a jury of sheep shearers of the mechanisms of an attack on a WEP secured link.