Zuckerberg has to answer for this

[JHan]

4. The denials concerned me,

Seems they were determined to save face instead of coming clean earlier.

It would have been difficult for them to know at the time though because buying ads on FB is an automated process. Hard to pin point who is doing what at the moment of transaction - although when the Clinton campaign touched base with them about the possibly that the proliferation of trolls were Kremlin funded operations , I would have thought they'd thoroughly investigate it then and nip it in the bud. I don't know if they wondered how that would conflict with their fiduciary duty to customers at the time.

Stil, the denials are curious.