Cambridge Analytica whistleblower Christoper Wylie, appearing before a committee of British MPs on Tuesday, said that Facebook has the ability to spy on users in their homes and offices. The British parliament is investigating Cambridge Analytica’s involvement in the Brexit election. MP Damian Collins, who chaired the committee, asked Wyle whether Facebook has the ability to listen to what people are talking about in order to better target them with ads.

“There’s been various speculation about the fact that Facebook can, through the Facebook app on your smartphone, listen in to what people are talking about and discussing and using that to prioritize the advertising as well,” Collins said. “Other people would say, no, they don’t think it’s possible. It’s just that the Facebook system is just so good at predicting what you’re interested in that it can guess.” He asked for Wylie’s thoughts on the possibility. READ MORE