How do you felt when your work infringed?

Alright, the purpose is to get the mood, actions/reactions of the author who spend enormous hours on making a work (video/audio/book/design) with passions & emotions well mixed, when their product is being circulated by pirate or someone using it without credit or money. I am working on technology that will help authors to send polite takedown notice (dmca like notice) (& much more) to infringers (websites) when the work is infringed.