Not illegal where? I'd be surprised if this wasn't copyright infringement in most USA-compatible jurisdictions.

USA?

"Making a noncommercial mix tape (as in, an analog audiocassette) of copyrighted songs is immune from claims of copyright infringement, thanks to the Audio Home Recording Act of 1992, 17 U.S.C. § 1008."

Does it mention creating bit perfect mix tape clones and redistributing to unlimited others?

Some info here...

http://jolt.law.harvard.edu/articles/pdf/v07/07HarvJLTech377...

most of my music is not bit perfect though... they are compressed mp3's of decent quality (but if you look at the bits, they probably look nothing like the originals)