I have no way to verify whether the collective really helped the violent acts that are cited in the designation[1] but, as an Italian, given the dialectic and rhetoric in their statements and in their websites, it would not surprise me if this once they - the US government - were not wrong. "A broken clock marks the right time twice a day" and all that.
I have experienced this kind of language personally back when the collective started (they have root in the no-global movement, a protest group that contributed to the violence at the Genova G8).
At the time I was a young activist on their side, but the 'we are not violent' wink-wink nudge-nudge attitude was not main stream but very much all over the place and became hard to ignore.
[1]https://www.state.gov/releases/office-of-the-spokesperson/20...
edit: forgot the link to the designation