In violating copyright, there can be contributory infringement and vicarious infringement, in addition to actual infringement. These are fairly simple to understand. Contributory infringement occurs when you enable infringement. That is, if a tool facilitates the act, then that tool infringes. Vicarious infringement occurs if were able to prevent the infringement and were in a position to profit from the infringement.
Tools that facilitate copyright violation include, but are not limited to,