Internet piracy act of reproducing and distributing copyrighted material. It is illegal because it is copyright infringement. Copyright is the legal right for being a creator of a piece of information. It gives you the right to decide under various conditions you want your work be reproduced or used by anybody else.
If anyone reproduces or distributes any copyrighted material without being authorized by the creator of such material, it has become copyright infringement which means you have infringed on his right to be only custodian of whatever benefits on such material.
Copyright infringement is illegal act which is punishable under the law. While many believe internet piracy is an illegal act, some people are of another opinion, saying since the file copied either information or music does not totally remove the copyrighted material, it shouldn't be considered as theft, instead it only copies the material and the copyrighted material can be found again on the internet