  We carefully consider the Shapiro time delay due to black holes and
shockwaves in de Sitter spacetime and study the implications for causality. We
discuss how causality conditions of AdS and flat spacetime can be applied in de
Sitter spacetime, using spatial shifts measured on the boundary to define
``fastest null geodesics" and taking into account the ``stretching" of the de
Sitter Penrose diagram. We consider the propagation of a massless spin-1 field
with an $RFF$ coupling in a de Sitter shockwave background as an illustrative
example. We also briefly discuss connections to the ANEC.
