if you make a thing and the thing is going to be inevitably used for a purpose and you could do something about that use and you do not --- then yes, it exists for that purpose, and you are responsible for it being used in that way. you don't get to say "ah well who could have seen this inevitable thing happening? it's a shame nobody could do anything about it" when it was you that could have done something about it.
Yeah. Example: stripper poles. Or hitachi magic wands.
Those poles WERE NOT invented for strippers/pole dancers. Ditto for the hitachis. Even now, I'm pretty sure more firemen use the poles than strippers. But that doesn't stop the association from forming. That doesn't make me not feel a certain way if I see a stripper pole or a hitachi magic wand in your living room.
In this case we're debating whether one of the purposes of AI is to scan the elderly. Probably 'purpose' is not quite the right word, but the point would be: it is not the purpose of AI to not scam the elderly (or it would explicitly prevent that).
(note: I do not actually know if it explicitly prevents that. But because I am very cynical about corporations, I'd tend to assume it doesn't.)