The issue is
the aggregation and collation of the data and making it
available to others. Why would you consider that some one's edit history
is any less personal than what they borrow from the library?
...
Why so? Editing history reveals your interests,
maybe your politics,
perhaps your religious affiliations, your ethnicity. A whole range of
personal data can be mined from 1000s of edits. It may reveal
associations with other users, and networks of users. Those groupings
may then be traced into social networks like facebook, or linkin.
If you borrowed books from a library with the reasonable expectation of
privacy, and such data was made public, I can see the issue.
However, if you borrowed books from an open and public source, (
bookcrossing.com comes to mind) which shows you, and everyone else, every
book you've logged into the site, you really can't reasonably expect
privacy.
Its not a question of expecting privacy its a question of requiring
privacy. Did you see the proposed EU document and how it would impose
liabilities on individuals that aggregate and disseminate personal data?
At present adoption is delayed until next year as it appears that member
states are looking to toughen up the rules and penalties: