Maybe someone in this section can help.....?

I have asked this in other sections and no one really knows the answer. Ok so here is the rundown. About 1 1/2 years ago, moved to new apartment. Neighbor had wireless. He said we could use it if we picked it up (unsecured network). Since our comp was not wireless capable we (fiance and I) went out and bought a Belkin wireless thumb drive to pick up the wireless signal. SO year or so went by. Economy went to poop, he didn't pay his bill. So when we try to sign on to his signal "zach" it comes up with this Comcast page, saying if your a customer how to pay your bill, or get your internet up or if your a Comcast technician.So then instead of signing on to my neighbors network I sign on to "belkin45g" and I have internet. I don't just have internet I have pretty fast internet, fast and strong enough to play a FPS on my PS3 with minimal to no lag.

Additional internet info. We have many secured networks in our apartment complex. Other networks are pretty strong signals. I have just really been wondering how I have internet. Hope you can help. Thanks.