I know Calibre can remove DRM, but it seems that Calibre does not remove things like watermarks, references to the buyer by name, etc. Now maybe I can try to find those manually, but that is an error prone process. Plus, what if they embed a unique digital signature that ties back to me? I understand that this is a very uncommon practice, but I do not want to find myself in a bad place.
I suppose the only way to remove a digital signature of any sort is to buy two of the same e-book by different people, diff them, and remove anything that differentiates them.
Is there any tool that does this or automates the process? am I being too paranoid, and this is not a real threat?
Diffing should reveal any differences, even white space. I suppose with white space it may be harder to fix, as you have to figure out the neutral state. But it is still possible.
Regarding the time stamp, I actually did think of this and you’re right. It would work especially for a small online bookstore. I believe the two books just have to be bought at very different times and ideally different other things, like people with different last name and even general location of billing address.
Regarding your other points… You make good points, so I will consider.
i have to admit, that my point ‘just don’t do it’ in reality does not garantee to prevent any trouble. it still is possible to be sued for things someone else did.
also one suggestion to think about:
if the seller just sprays some random changes over a book for every sold version, one would have differences in “every” sold version to every other sold version. by blindly changing those parts to something else you could reveal which exact two/three versions you had for diffing.
UPDATE: someone else here had the same thought a bit earlier…
my suggestion to not do it stays the same ;-)
it could be interesting to figure things out how they work, what could be done to prevent or circumvent such prevention, but actually doing it seems risky no matter what.