Let me tell you, I didn't even know the "Custom Audience" ad feature even existed on FB until yesterday. In fact I'd somehow missed seeing the ad preferences screen entirely, so I spent some time on that yesterday looking at all the data categories FB has put me in (rather terrifying in and of itself) and saw the bit about "advertisers who submitted your contact information" or whatever it says, and I was like WTF is this?

Here's what disturbs me so much about this — dozens and dozens (possibly hundreds) of companies that were listed there for me I have never interacted with, many of which I'd never even heard of. So obviously these companies purchased third-party email lists, which themselves might have been purchased...who knows...the point is I never directly consented to any of these companies having my email address. BUT, now that they do, they are able to use those lists to target ads to me directly on FB. I consider that spam. If I get unsolicited emails from marketers, that's spam. Therefore, if I see unsolicited ads on FB due to them targeting me directly through my email (or phone number?!), that's spam!

I feel like the vast majority of FB users, and possibly many of the current critics of FB in the media or in government, aren't even talking about this horrible spam problem. In my opinion, Custom Audience is simply evil and should be obliterated from the FB ad platform.