Well, unfortunately, this "money" you speak of is not of infinite supply. Some people might make decisions on principle, but most people either can't be bothered or simply can't afford to. Life usually isn't that convenient, and companies know it.

That ruling was only against companies who advertised the fact that you could download illegal material (like Grokster did). If your product doesn't advertise the swapping of illegal files, you can't be held responsible (legally, anyway).

This also brings back the old argument: Don't arrest the gun company for making the gun that killed a man.