Privacy advocates raised concerns about this practice; concerns included that allowing email content to be read by a machine (as opposed to a person) can allow Google to keep unlimited amounts of information forever; the automated background scanning of data raises the risk that the expectation of privacy in email usage will be reduced or eroded; information collected from emails could be retained by Google for years after its current relevancy to build complete profiles on users; emails sent by users from other email providers get scanned despite never having agreed to Google's privacy policy or terms of service; Google can change its privacy policy unilaterally, and for minor changes to the policy it can do so without informing users; in court cases, governments and organizations can potentially find it easier to legally monitor email communications; at any time, Google can change its current company policies to allow combining information from emails with data gathered from use of its other services; and any internal security problem on Google's systems can potentially expose many – or all – of its users.