Wireless Network Question

[CrazyDe1]

So I'm sitting here surfing on what seems like my neighbors wireless connection because my roommate stole our cable modem. Anyways, there's 2 available wireless connections I can kind of get from my house. The first is obviously a neighbors as the IP I'm getting is 192.168.0.101 - obviously a router address. The 2nd though is kind of weird as I'm getting a 12.253.xxx.xxx IP which is ah straight attbi IP. How is this happening?