Someone told me WFilter can not block bittorrent downloading. So I did some research yesterday.
I downloaded both bittorrent and bitcomet from their official website. I also downloaded an availble torrent file from bittorrent.com.
Turning "Block P2P" on in WFilter console, then use bitcomet to download, the download never begined. However, when I use bittorrent to download, it will start downloading after trying for a few seconds.
This is really interesting. Since WFilter can detect and block bittorrent traffic using pattern match, this should not happen. So what's the reason? After detailed analysis of the network traffic, I found bittorrent also download data directly from bittorrent.com using http protocol. That means bittorrent not only use p2p downloading, but also can download files directly from the website.
Knowing that, I added "bittorrent.com" in the black list of wfilter's website black&white list, then did the download again. Aha, bittorrent never be able to download any files.