“Microsoft omitted important information from its blog post today,” Google wrote in a statement. “Microsoft uses a ‘self-declaration’ protocol (known as ‘P3P’) dating from 2002 under which Microsoft asks websites to represent their privacy practices in machine-readable form. It is well known – including by Microsoft – that it is impractical to comply with Microsoft’s request while providing modern web functionality. We have been open about our approach, as have many other websites.”