I learned that because I own a handful of shares of Arconic, which is a company in the midst of a hostile takeover attempt. I was rather curious how FB figured that out... but both sides know my identity, and apparently whatever I agreed to when I opened a brokerage account included giving my identity to companies I invest in, and them giving it to activist investors, and the company/investors giving it to social networks.
My understanding is that in the US at least, it's common for both parties to attempt to maintain complete databases of all voters, so it's feasible for them to select individual ad targets themselves and just give FB the names.
This guy pranked his roommate with targeted Facebook ads - http://ghostinfluence.com/the-ultimate-retaliation-pranking-...
You can build up a whole chain of audiences. For example, if you watch a video ad, you can then be targeted. If you, say, click a link as part of that audience, you can find yourself inside an even tighter targeted audience. At that point, you're considered hot. Before you know it, you could be buying a product. At which point, you're in another audience still, tempting you to buy again!
In fact, with this type of targeting, interest and demographic based targeting doesn't even come close. You can, however, target all the people, at each step in your funnel, who "look like" people who wanna buy (have the same interests, age, gender). These get fed back into the top of your targeting funnel and so it goes.
As for the UK GE, I'm not seeing this type of targeting so I think they may be stuck in the "old" interest-based model of FB advertising.
edit: and it probably wasn't the class action you're thinking of :)
Why would you trust your Facebook account (or any other account) to a random stranger on the internet you've never met, heard of, or even seen? Whose real name you probably don't even know?
I'm not saying there isn't any utility, but I don't think it's obvious enough from reading the front page of the site.
From the Guardian article [0]:
"It aims to show who campaigns are targeting, how much the parties are spending and will shed light on whether targeted adverts are crossing the boundary into 'fake news'."
[0] https://www.theguardian.com/technology/2017/may/03/free-soft...
Their privacy policy is here: https://whotargets.me/privacy-policy/
Facebook is very different. There was apparently a lot of very sophisticated targeting going on for Brexit.
(There are a number of conservative MPs under investigation by the police for violating spending limits, plus a developing story about money laundering from HSBC: https://www.thecanary.co/2017/04/28/breaking-dark-money-hsbc... )
I had read an interview the one of the UKIP social media guys talking about that US company that provided services to the leave campaign. he shut his own facebook down after hearing about how it worked
