It was routinely being used in this period, and, of course, still is routinely used -- because there were no complaints about it, not within the context of this study, anyway -- it was routinely being used to deal with people who were violent, who were potentially violent, and also quite frequently used to deal with people who were simply passively noncompliant.
Veniva usato regolarmente in quel periodo, e, ovviamente, lo è ancora -- perché nessuno si lamentava, e comunque non nel contesto di questo studio -- veniva usato regolarmente per contrastare le persone violente, quelle potenzialmente violente, e di frequente anche quelle che facevano semplicemente resistenza passiva.