why piracy is such a menace?

downloading music from the sites which offer free music downloads is not piracy. but if they offer the softwares such as torrent sites then it is a piracy and this is bad as the softwares are made after so much hardwork and the works involved by the companies. they copyright their softwares so that no one can use it illegally but they r posted on torrent sites and we use them and that is a way that hampers their research and hard work. the amount they can earn by selling it is lost somewhere due to the piracy so they suffer loss. piracy should be stopped and this should begin by the microsft windows that we are using on our system. windows is used most widely and it is pirated in most of the cases.