This list is by no means exhaustive, and merely aims to catalog as many super-radical left-wing organizations as we can find which may be considered radical enough to be considered terrorist organizations. This doesn't necessarily mean they ARE, it just means they need to be looked at very closely. So, with that disclaimer out of the way, let's get into it.

1. Antifa (AKA The Torch Network, AKA Torch Antifa Network) - The radical anti-government extremist leftists. Most white people who are nihilists and just want to burn things to the ground end up here. Torch is the network hub around which local chapters organize and communicate.

2. Muslim Brotherhood - The really big leftist Muslim-centric organization. Radical leftist Muslims end up here.

3. Black Lives Matter - The really big leftist black-centric organization. Radical leftist black people end up here.

4. Redneck Revolt - Another radical "anti-fascist" group which has been implicated in many volatile confrontations. This is the "pro-2a" leftist group that believes in arming yourself to protect against the far-right. The serious gun nuts end up going here.

5. John Brown Gun Club - Similar to RR. They and Redneck Revolt often work as armed security for radical leftist events.

6. Earth Liberation Front - Eco-terrorists. Radical leftist environmentalist freaks end up in this group. They don't seem to be super active these days but they still might be out there. Mostly because big money interests corrupted left-leaning movements with legitimate and real concerns and big money doesn't care about exploiting the environment all that much.

7. Animal Liberation Front - Radical leftist animal rights activists. Maybe these people had something to do with all the food processing facility shenanigans? They've committed many acts of violence as well.

8. Open Society Foundation - The white collar administrative wing. Your high-educated 'intellectuals' and more prominent businessmen end up here. Generally not going to be implicated in on-the-ground riots, but is going to be financing things and pulling the strings on policymakers and other things at higher levels, and doing stuff in the background.

9. By Any Means Necessary - Another militant far-left group which has been implicated in many protests and other kinds of subversive activities. Has thought to be involved in terrorist activities since 2005.

10. The Revolutionary Communist Party, and its child organization, Refuse Fascism. They pretty much openly organize for overthrow of capitalism and replacing it with world communism. So, yeah.

11. Smash Racism DC - Highly involved in the DC area and organizes many militant protests.

12. It's Going Down - Pro-Antifa media outlet that covers events and acts as a publishing platform to disseminate radical leftist news.

EDIT - Part 2 - This part is mostly financiers and donors, not direct action / on-the-ground groups.

13. Ford Foundation - Big money donor foundation, just like OSF. Everyone knows who the Fords are.

14. Rockefeller Brothers Fund - Another big money donor foundation like OSF and FF. Everyone knows who the Rockefellers are.

15. Tides Foundation - Also a donor organization and is also a little closer to some direct action groups than OSF / FF / RBF.

16. Charles and Lynn Schusterman Family Philanthropies - These philanthropies have supported criminal justice reform and voting rights groups that participate in large-scale protests and mobilizations, particularly on racial equity and reproductive rights. So, these are the assholes who are responsible for Decarlos Brown Jr. running around rampant.

17. Morton K. and Jane Blaustein Foundation - They donate to progressive groups which often have protest and action-oriented divisions.

18. Omidyar Network - They fund media stuff primarily, but they also fund causes that overlap with protest movements and rub elbows with a lot of the same people.

19. Knight Foundation - Funds a number of different progressive and lefty groups that in some cases organize direct action efforts.

20. MacArthur Foundation - Funds a number of different progressive and lefty groups that in some cases organize direct action efforts.

21. Anti-Racist Action AKA Anti-Racist Action Network - This is the more global wing of Antifa, which is based in the US and Canada. Since it has cells in Canada, too, Torch Antifa was developed as a separate sub-network in order to (hopefully, good luck!) evade designation as a foreign terrorist organization, thus sheltering them within US domestic law. I'm fairly sure this is an older incarnation that isn't as relevant these days.

22. One People's Project - Primarily digital group that does stuff like doxxing.

Feel free to add your own.