It can sniff and crack WEP and WPA protected networks but in order to do that you will need a USB 802.11 WLAN dongle that is AirPcap Driver compatible. For doing middle man attacks its awesome, the same applies for cracking windows passwords remotely, all you need is to capture the hash and then you right click it and select "Send to cracker". I learnt all the tricks of cain and abel by reading their help file that really helps alot.