The law says it is not theft, but infringement. You can't steal something that doesn't exist physically. Stealing means you took something from someone and they no longer have it. Copying intellectual work isn't stealing as the owner still has the original. Courts have ruled this is not theft. At any rate the award, or fine, is way in excess of the so called "loss". I say so called because this kid would never have bought the 30 songs if he couldn't copy them and so they didn't really lose anything.
Courts have distinguished between copyright infringement and theft, holding, for instance, in the United States Supreme Court case Dowling v. United States (1985) that bootleg phonorecords did not constitute stolen property and that “interference with copyright does not easily equate with theft, conversion, or fraud.
The Copyright Act even employs a separate term of art to define one who misappropriates a copyright... ‘an infringer of the copyright.’” In the case of copyright infringement the province guaranteed to the copyright holder by copyright law is invaded, i.e. exclusive rights, but no control, physical or otherwise, is taken over the copyright, nor is the copyright holder wholly deprived of using the copyrighted work or exercising the exclusive rights held.[1]”