Obey copyright laws. Sharing copyrighted material without permission is against the law. See Mind your P's and Q's to avoid copyright prosecution.
UC Berkeley's DMCA Designated Agent should receive any online copyright infringement allegations for UC Berkeley network locations.
No Electronic Theft Act clarified that willful online copyright infringements are punishable by severe penalties, even though the distributor makes no profit.
Disable any unwanted filesharing programs. Your computer may be set up so that it can share unauthorized copyrighted materials without your knowledge or consent. See Disabling Peer to Peer File Sharing.