“weaponized data from 200 million Facebook accounts.”
A monthly active user is someone who checks into Facebook at least once a month. According to Facebook, in the second quarter of 2012 there were 186 million monthly active users in both the US and Canada. In the third quarter there were 189 million in both the US and Canada. Probably 20 million of these were in Canada. It’s a certainty that no one had access to every single account on Facebook, nor would it mean much as a large majority had established political views and could not be swayed by anything.
In addition, as mentioned, the Obama campaign had permission to do so from people who used their app. The app Cambridge accessed did not, nor did they have permission to share it with Cambridge. This is a crucial difference.
I’m not sure what “weaponized” means.
Probably, the Obama campaign had access to fewer accounts than the Cambridge people did as there were many fewer people on Facebook at the time.