repress or suppress (something regarded as undesirable); "The police clamped down on illegal drugs"
To clamp down on people or activities means to take strong official action to stop or control them. If the government clamps down on the protestors, that will only serve to strengthen them in the long run Banking regulators failed to clamp down until earlier this month. = crack down
repress or suppress (something regarded as undesirable); "The police clamped down on illegal drugs