Who are they and what do they do?

state.gov - Designation of autistici inventati as a specially designated global terrorist

Today, the Department of State, in partnership with the Department of the Treasury, is announcing the designation of Autistici/Inventati as a Specially Designated Global Terrorist.

Autistici/Inventati (A/I Collective) is an Italy-based extremist group that builds and operates the digital infrastructure for violent Antifa cells and other far-left militants across the world. A/I’s cadre of radical hackers and tech developers provide a full spectrum of services – including encrypted chats and email, web hosting, secure video conferencing and streaming, anonymity shields, and a suite of other technological tools – to Marxist, anarchist, and other left-wing extremist groups in the United States, Europe, and elsewhere. These tools are specifically designed to support the operations of far-left terrorist networks, built to enable them to organize, recruit, communicate, disseminate propaganda, share target information and tactics, and carry out violent attacks – all while remaining anonymous, untraceable, and beyond the reach of the law.

And who do they supply their services to? A number of far left, violent groups including Rose City Antifa, Jane's Revenge and the bunch that wanted to shut down the law enforcement training center in Georgia.

I told you people that Antifa and other groups were getting help from foreign bad actors. And I was of course right.

Who else does the A/I collective support?
A far-left extremist media group claiming to be a “tool” for global militants to share “essential information” to be “acted upon,” relies on A/I Collective tools and services to publish official communiqués and calls to action for U.S.-designated foreign terrorist organizations such as Armed Proletarian Justice, Informal Anarchist Federation and International Revolutionary Front (FAI/FRI), the Islamic Revolutionary Guard Corps (IRGC), Hamas, Hizballah, National Liberation Army (ELN), New People’s Army (NPA), Popular Front for the Liberation of Palestine (PFLP), Palestinian Islamic Jihad (PIJ), and Revolutionary Class Self-Defense. This same group was recently cited in a federal criminal complaint against a domestic terrorist who was sentenced to 19 years in prison for targeting a federal building and police car with improvised explosive devices.

It's the 1970s and early 1980s all over again: left wing collectives supported by foreign networks carry out terrorist attacks worldwide, all united in their violence.

Antifa was never merely an "idea". It's a loose collection of like mind, violent freaks who are built on the IRA model of dissociated cells. Just like the IRA, they get aid from foreign groups of fairly high level sophistication.