Helpful Hacker
I heard about people trying to gain access to other networks and having fun (what’s fun about that???). Anyway, if it is a corporate network, it might make little sense because these sick people steal data, but what is the use trying to hack into home networks?
Well….sometime you are probably forced to use others network. Infact, I ended up doing the same couple of days back.
I was working doing an important firewall upgrade yesterday and suddenly my internet service from my ISP died on me. Several reboots of my cable modem didnt help. So I ended up using NetStumbler to determine the Wireless networks in my neighbourhood and selected a WEP Disabled Linksys AP and it immediately gave me an IP (DHCP was enabled on this AP). Then I completed my work. Thanks to this neighbor. 
I then got curious and tried logging into his Linksys AP and and found that he didnt change the default settings, including password. I later scanned the network and found that his C drive was shared. When I opened it out of curiosity, I ended up seeing many viruses files in there. So I placed a text file named ‘Read Me XXX’ (XXX is the name of his system which is his name) on his Desktop. In the text file, I told him what I had to do and asked him to secure his Wireless AP and clean the viruses on his machine. I signed the bottom saying ‘Helpful Hacker’ 
Today I scanned the network again to see the status of that AP. I was happy to see it Secured. But if I losse my www connectivity again, I may not get any help fom him 
Raju