Who said anything about a security breach? Most of the controversy has been about the company influencing elections using data scraped from people (and their friends) unaware of what the data was being used for.
The degree to which it influenced the election is questionable. Despite all the headlines, I haven't yet seen any convincing analysis of the impact of facebook on the election (I'm not sure how one would even go about doing so). So far it seems like it's just a convenient vehicle for people that dislike the outcome of the election to express indignation.
This is obviously unmeasurable - there isn't convincing analysis because there can't be convincing analysis, as you admit.
The fact that people were willing to spend an amount of money that breached electoral law in the UK, and presumably even more in the US, suggests that there was some reason for them to do so. This happened only because experts in this field believed it would influence the outcome of the election.
That's interesting. How would he know the degree to which he influenced the election? Believing any claims to somehow fact rather than plain old self-promotion seems rather naive, or am I missing something?
Even if we presume those sentiments are completely sincere and disinterested, I don't know why we should believe he is an authority on US elections whose claims can simply be accepted at face value.
