The one who says free downloading is harmful is don' t know what is like moneylessness or is the one who makes loss from free downloading. I can give you at least two reasons for why free downloading must be legal.
1. Original mp3s, films and other stuffs are too expensive to afford for many people. Moreover, access these stuffs from the Internet is easier than find originals from the Internet or place of sale. For example, I can reach any film or song from downloading program and download it swiftly but when I search it on the Internet, I have to do lots of procedure things.
2. Celebrities can make profit from live performances. They can give concerts or gain money from box-office receipts. Thus it provide benefit to both celebrity and us.
Some say, free downloading must be illegal because famous people can' t gain money from that. When their productions are free on the Internet, no one will buy originals and give money. But if free downloading is illegal, celebrities make a loss instead of make a profit. Because people will think their stuffs are too expensive and they won' t buy them, and because of free downloading is illegal neither can download them.