To check for specific downloads in this case Torrent Files from the Internet use this option in the URI field of the Top Websites & URI report. This is located in Plugins \ Web \ Advanced Reports
The module Web Client detection includes a number of reports that can detect bittorrent clients such as limewire, utorrent etc...
Version 8.3 of the LANGuardian introduces a new BitTorrent event type to assist in identifying BitTorrent activity on the network. A new event type has been added to the Security Events ::By signature report. The BitTorrent Announce request event identifies BitTorrent peers contacting a tracker site to initiate a download of some media.