The New York attorney general’s office plans to launch a probe into Facebook’s collection of the email contacts of 1.5 million users, The New York Times reports. The investigation will reportedly focus on how the contact collection happened, and if the data harvesting was more widespread than the company stated. The newspaper reports that almost 2.4 billion people use Facebook each month, and 1.56 billion people visit the site at least once a day. Earlier this month, Business Insider reported the social network accumulated the email contacts of a portion of users who signed up after 2016. The contacts were reportedly used to improve Facebook’s ad-targeting and make friend suggestions. The company told the website the data collection practice was “unintentional,” and a mistake that stemmed from a system the company once used to verify new users. Facebook reportedly did not respond to the Times’ request for comment.