Police deliberately escalated Yip-In violence and attacked the press.

Evidence

There was no warning. Having sealed Grand Central’s main exits, the police—evidently responding to a signal from the commissioner himself—forced Bob Fass’s “cabal,” as well as the Yippies, the Motherfuckers, and everyone else to run a gauntlet out a single set of side doors. Nor was the press spared. It was no longer the Yippies’ show. “All the brass was watching,” Don McNeil began his report, which reached its climax with four cops cursing the Voice and deliberately ramming his head into (and cracking) a closed glass door. — J. Hoberman, Everything Is Now, 1209

Categorization

• ADDENDUM: Skyrocketing police escalation against countercultural gatherings serves as material conditions shaping the scene — relevant to the reader’s test-case framework for what conditions produce art density.