Sharing with friends via a server is as much copyright infringement, legally speaking, as sharing with randoms on bittorrent. Its just much harder to prove, much less financially beneficial to prosecute and much worse PR if you do it anyway to set an example.

> legally speaking

as usual, this depends on where in the world you are. Some legal systems do make a difference here.

I don't think so because it is not illegal to give them a copy on a cassette

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)