The interesting question is what happens when Turkey asks for the members of a "justice for unfairly sacked teachers" petition, or Saudi Arabia asking for the supporters of the local "End discrimination of Shia" petition.
I'm more concerned about political operatives right here at home who are likely rubbing their hands with glee, as FB gives them the tools to make it easier than ever to drum up online lynch mobs to further poison political discourse.
I'm not even going to mention how much easier this makes it for scammers to find their marks. The guy who collected $20m on Gofundme for 'the wall' comes to mind.
Can you explain how this guy is a scammer? It looks like everyone who donated before the Gofundme plan switched from "donate it to the government" to "pay to build it ourselves" is having their money automatically refunded to them unless they explicitly opt in to the new approach, and donations still keep rolling in from people opting in to this new we'll-just-build-it-ourselves approach. Where's the scam?
The Russians proved how easy that is. Putin has been doing this internally for a very long time before messing with the 2016 election. Create a pro-gay group, create an anti-gay group. Foster hate between them. Others join the respective "causes" that they align with. You now know a lot of the pro/con supporters because you're running the group(s).
Here's an 11 minute clip from Adam Curtis' HyperNormalization, which illustrates this tactic: https://www.youtube.com/watch?v=kwglZTNhMNE
It's alive and well in the USA too, and things make more sense after watching it. I'd find the whole video and watch it. It's quite fascinating.