Robert Mercer funded a group that stirred up fear by showing Islamist conquest fantasies, targeted at US voters likely to be manipulated by them. The group seems to have omitted this spending from its tax return, too.

When Russia manipulates US elections, that adds an extra factor of foreign intervention. However, this sort of manipulation is an attack on the fairness of the electoral system no matter who does it.

Facebook has announced a system of labeling political ads and verifying the official identities of their purchasers. This labeling may do some good, but (as the article explains) it won't be hard to create an intermediary to hide the real identity of the real purchaser.

Companies that implement targeting of ads should be required to show the public all the ads that each customer has placed, collected in a place easily found from the name of the customer, and the whole collection should be easily searchable.

Robert Mercer and his daughter Rebekah work on their right-wing extremism together. The American Museum of Natural History should recognize this as one more reason to remove her from its board.