And also wireless clients that don’t need to be close by. All I’ve got is a cheapo USB client from ebay, about £25 i think. That can see access points half a mile away. My old boss had a directional antenna he bought for about £100 which could see and communicate with AP’s well over a mile away. He lent it me once, I did a scan at home and found around 200 AP’s.
In that instance a hacker would select the low hanging fruit, probably start attacking the WEP AP’s while letting the WPA brute forcing run on a different machine the background. You only need to capture one hash from each AP to run your offline cracking.
Note that a hacker is almost certainly not interested in stealing your bandwidth. They’ll be after two things.
1. Breaking into machines on your network without fear of capture
2. Using your connection to attack other, higher profile targets without fear of capture