When considering Antifa we have to take into consideration possible goals with the knowledge that the people in power often use indirect means.

Antifa does not seem to be targeting establishment politicians and instead are targeting the people that oppose them.

The establishment law enforcement has largely turned a blind eye to Antifa terrorism including arson of the homes of people that question the establishment governments.

Antifa's attacks on civilian dissenters will justify a government crackdown on anonymity (Antifa wear masks) and protests in general.

Based on what limited information I have about the G20 protests and Antifa in the USA it is too early for me to say, definitely, that they are a proxy tentacle of the globalists. Given more information, however, I think one could easily use inference and deduction to build a clear picture of who is controlling Antifa.

In the USA we call this kind of reactionary manipulation conspiracy and it's a crime, if only on paper.

Historically, the similiarity to the mobs that violently shut down opposition to Mao and Antifa are very disturbing.