A few days ago, a post at Publishing Perspective was talking about
Watermarks for ebooks.
(edit
I know that Watermarks are DRMs, more specifically "social DRMs". Nonetheless, for discussion simplicity, I'll address "Social DRMs" and " Encryption-based DRMs" as (respectively) Watermarks and DRMs.
Two questions :
First one is for all readers here: what do you think about them ? How do they compare from your side against DRMs, and against no "copyright protection" at all ?
Second one, for DRM specialists, I seem to remember that the epub DRMed files contain nominative information, or at least some that can be traced to the "customer", and that the DRM removal tools don't remove this information. Is that right ?
And it it the same with mobi/azw DRMs ?