Specifically, follow him around asking why he campaigns to lower the age of consent to 14, and is on record that "it is time society acknowledged the truth that not all sex involving children is unwanted, abusive and harmful".
Richard Dawkins might also be followed around and asked what formation in the Augustinian doctrine of Original Sin was given either to Stalin or to Mao, just for a start, and how he knows that the human species did not descend from a single pair. Then again, despite the BBC's reporting of their childish scream for attention as Saturday's main event (though with the numbers couched in such terms as "up to"), are they really worth bothering with after the spectacular failure of their campaign against the Holy Father's visit?
Definitely worth bothering with, however, is the persistent use of the term "stem-cell research" to mean scientifically worthless but morally abhorrent playing about with embryonic stem cells, together with the viciously cruel justification of this by reference to an ever-longer list of medical conditions. The real stem-cell research involves adult and cord blood stem cells, is ethically unproblematic, and has already yielded real results, but struggles to secure funding because it is of no interest to those who cannot forgive the Catholic Church either for having educated them or, as in the case of Richard Dawkins, for having educated the wrong sort.