I thought the Sedition Act had been ruled uncostitutional by the SCOTUS shortly after WWII ended or was it after Korea Got started, anyways that's why we couldn't use the sedition act aginst the Nam Peace-Niks and Fondue Funnies.
However, I viewed part of the video (as much as I could get to play) and those in the group were openly making seditious statements.
Perhaps NYPD could haul them in for disturbing the peace, failing to heed an order from the police to disperse, terroristic threatening, resisting arrest and littering. Mugshots, fingerprints and ID checks....the whole nine yards!