I had a wireless question...

I have an unused wireless card built into my laptop, so this weekend I decided to install Netstumbler and see what's out there. I found an open, unencrypted, DHCP-enabled wireless access point pretty close to where I live (about 100 meters to the ocean in a hidden corner of the Vancouver area).

Now...how do I tell if this is an intentional access point for people to use, or a misconfigured wireless router? Since it's running on cable internet and I don't wanna get whoever runs it in trouble, I don't want to call his/her ISP to find out how to contact them.

Seems to me that this is an important bit of missing info on wireless community sharing.