If you infringe a patent:
3 and 4 are both possible
3. the owner of the patent will sue you in a court
4. nothing may happen
Why? In most countries, infringement of a patent is not a crime. That is, it is not a wrongful act against the state and therefore, an infringer does not go to jail. Infringement of patent rights is a civil wrong committed against a person or entity. Enforcement of patent rights is left to the owner of the rights. Thus, it is up to the offended party, usually the owner or the exclusive licensee of the patent, to seek a legal remedy for the violation of the patent rights. Nothing may happen if the patent owner does not become aware of the infringement, or if a business decision is made not to take any action against the infringer of the patent. In the case that the owner of the rights does choose to enforce the rights, it is often possible to settle the matter with the infringer out of court. Alternatively, a suit may be filed against the infringer in a court. The remedies that a court may grant for a patent owner include injunction (an order to stop the offender from doing the wrongful act), account of profits (payment to the patent rights holder of the profits made from the infringement of the patent, or some percentage of them in lieu of royalties), and award of damages (monetary compensation to the owner of the rights).