There isn't a loophole with the graph, it was designed for this and was used notably by Zygna and later the Obama campaign. When the campaign hoovered up everything in 2011/2012 and set off alarms, FB saw what they were doing and didn't hinder it. Instead they reached out them, stating that they're on the same side. Hopefully these links aren't mangled.

Here's the media championing it:

"How a dream team of engineers from Facebook, Twitter, and Google built the software that drove Barack Obama's reelection"

https://www.theatlantic.com/technology/archive/2012/11/when-...

"How President Obama’s campaign used big data to rally individual voters."

https://www.technologyreview.com/2012/12/19/114510/how-obama...

"Obama, Facebook and the power of friendship: the 2012 data election"

https://www.theguardian.com/world/2012/feb/17/obama-digital-...

"the firm never tried to stop them when they realized what was doing, and even told them they'd made a special exception for them"

https://www.dailymail.co.uk/news/article-5520303/Obama-campa...

"Why are politicians now freaking out about a feature that has been publicly documented since its inception and that was discontinued three years ago?"

https://reason.com/2018/03/23/cambridge-analytics-dust-up-re...