If the 2016 election taught social media platforms anything about their responsibility to prevent the spread of malicious disinformation, the companies still aren’t sure what, exactly, to do about it.

At least that was the consensus at a panel discussion Thursday night at Stanford University, featuring high-profile policy and communications representatives from Facebook, YouTube and Twitter and attended by about 100 people. The key question posed to each company representative, as well as audience members, was “Does digital misinformation pose a threat to democracy?”