What we are a seeing is the normalisation of police brutality; and police brutality being used as an instrument of public policy.
Kettling is the process of mass arbitrary arrest by means of detention in street holding pens; incarceration lasts for several hours without food, water, shelter, toilet facilities or medical attention. Often those subject to detention suffer baton beatings and other assaults.
Precisely because this assault on personal and civic liberty has become normal, it is no longer newsworthy.
Kettling is a form of collective punishment in order to intimidate demonstrators and anybody else thinking of protesting in the future. Police now prefer collective punishment through kettling to attempting to apprehend wrong-doers.