My friend and sometime-colleague Martin was on morning report talking about this the other day:

http://www.radionz.co.nz/national/programmes/morningreport/audio/2018636999/the-facebook-cambridge-analytica-saga-explained

He makes the very good point that the bigger issue is the opacity of Facebook itself, and the way it allows campaigns to send _huge_ numbers of highly targeted messages to individuals. These messages could be contradictory, or dishonest, playing to the worst dogwhistle demographics. It has the potential to be _really_ corrosive to democracy.

How much of a problem is it? Who knows. There's no good way to analyse the impact because facebook won't release any info about what people are exposed to on their platform.

We had a rushed attempt at it last year, in the run-up to the UK general election.
I wrote a browser add-on which logs what consenting volunteers see when they're on facebook, so we could try and see which messages were aimed where. But really it's a drop in the bucket - too-small sample size and it completely misses mobile exposure.
(Still, source code here if anyone wants to try something similar:
https://github.com/bcampbell/facelog ;-)

But the CA stuff, apart from general scumbaggery and some legally-dubious actions is a bit of a sideshow.

I had a job interview at Xtra in what must have been mid-1995. I thought they were up and running at that time, but I guess I must be wrong if they launched in '96.

(Luckily, I flubbed the interview completely - I'd come down with some nasty bug and rolled up feeling utterly wretched.)

In order to avoid exposure to any UK media coverage of the election, I took the wise precaution of retreating from the UK to a safe location (Christchurch).

I've also been writing code to safely read the UK newspapers automatically, without risk of human exposure.

My less fortunate colleagues back in London have been doing a weekly analysis of the media coverage, using my data. Their roundups are published at electionunspun.net, if you're interested.

(There's also a summary of some of the data in yesterdays Guardian. It's astounding how rabidly partisan most of the UK press are - they're way more blatent about it in the wake of the Leveson inquiry into phone hacking.)