Plans by Google to create the world's largest library of digital books face intense scrutiny after civil liberties groups publicly questioned what the company plans to do with user records.
The American Civil Liberties Union and the Electronic Frontier Foundation, among others, wrote to Google CEO Eric Schmidt late last week urging him to make sure reader privacy would be protected.
Of particular concern is the service's ability to monitor exactly what Google Books readers are doing with the service.
The letter explained why: "Under its current design, Google Book Search keeps track of what books readers search for and browse, what books they read, and even what they 'write' down in the margins."
Google responded on one of its official blogs by asking for patience and promising that the safeguards will be put in place when a pending agreement with authors and publishers is finalised later this year.