I think that to emphasize "weaker beings" in any way would be a negative... already, in the minds of some, cyclists represent the "40 year old virgin." Of course, the real irony is that cyclists, exercising routinely, could probably kick butt on many motorists that are only "strong" due to the size of their SUV.
No, a better "crying indian" type campaign would be to remind people that cyclists are brothers and sisters, mothers and fathers, generally people you know... not just faceless cycling bots out there to create havoc on the road.