Originally Posted by uk.engr
Ok but on some website I read that it require BitTorrent protocol for peer-to-peer share en.wikipedia.org/wiki/BitTorrent
What will your suggestion?
As acid_kewpie said, you block torrents from the firewall level. Specifically an layer 7 filter is what you'll need to block bittorrent downloads. This has been asked and answered many times on this site before.
Squid is an HTTP proxy....so if a protocol is NOT HTTP, there's little Squid can do.