A cease and desist letter is a letter which formally requests someone to cease infringing upon your intellectual property rights, with a threat of legal action in case of failure to comply.
Stop someone using your intellectual property without permission by sending this cease and desist letter. Receiving a professional, succinct cease and desist is often enough to stop an offending party infringing your intellectual property rights. If not, you will have proof that you tried before resorting to the legal system. This letter covers details of the breach and an order to cease infringing action.