I would agree that is implied in the call for SETI to target them. The implication is the spread of a civilization to "nearby" stars could be responsible for th

I would agree that is implied in the call for SETI to target them. The implication is the spread of a civilization to "nearby" stars could be responsible for the observations. Without anything but wild guess to go on much closer transient (natural) obstructions in our line of sight could cause dips in a small region too. I would like to think we have some way to rule this out. Or further fetched, common formation seeded them with "something peculiar" and they are still neighbors. But again much like the GP question of what is the avg dist between what is common about their size age, composition etc, other than they seem to (slowly) dim?