There is an interesting thread on the pp.int.general mailing list.
A user claims that some emails in his Gmail account containing MP3 files were removed.
He admits that the removed files were copyrighted material. He also confirms that there was some indie music also which was not removed.
The user honey escreveu added:
> I cannot believe that Google scanned my user account files and removed
> content w/o my consent, besides my agreement to have an account with
> them. I suspect they used whatever scanner engine they have, which
> they use to scan files when you upload them to youtube, and they
> detect copy-protected materials.