Copyright infringement is only associated with stealing because of propaganda making that comparison for shock value and to try and make common folk understand it's wrong (because almost everyone immediately perceives stealing as wrong).
"Copyright holders frequently refer to copyright infringement as theft. In copyright law, infringement does not refer to theft of physical objects that take away the owner's possession, but an instance where a person exercises one of the exclusive rights of the copyright holder without authorization. Courts have distinguished between copyright infringement and theft. For instance, the United States Supreme Court held in Dowling v. United States (1985) that bootleg phonorecords did not constitute stolen property. Instead, "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.'" The court said that in the case of copyright infringement, the province guaranteed to the copyright holder by copyright law – certain exclusive rights – is invaded, 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."