Fetching details from the dictionary...

to manage; to control; to supervise; to oversee; to command
to crack down on; to keep under strict control; to enforce; to regulate
警察が違法行為を取り締まる。
The police crack down on illegal activities.
警察が交通違反を取り締まっている。
The police are cracking down on traffic violations.
飲酒運転を取り締まるための法律が強化された。
Laws to crack down on drunk driving were strengthened.