Screenshots and copy-pasted quotes of the text will not carry watermarks with them... unless maybe you are referring to the proposed watermark that involved changing the story subtly for each purchaser. I don't think that one got much traction.
And if you did post the watermarked CSS, or perhaps used the ScrambleEbook calibre plugin and uploaded the results? The only people who will know who you are, are the publishers/vendors who have the
restricted user database which matches watermarks to users. And not only do I very much doubt they care enough to find that book, I cannot feel too fussed about the privacy reveal involved.
But... point taken. For a very, very, VERY arguable value of "point".
