What should I ask Cass Sunstein?

Yes, I will be doing a Conversation with him soon.  Most of all (but not exclusively) about his three recent books Liberalism: In Defense of Freedom, Manipulation: What It Is, Why It Is Bad, What To Do About It, and Imperfect Oracle: What AI Can and Cannot Do.

So what should I ask him?  Here is my previous CWT with Cass.