clamp down, crack down (verb)
repress or suppress (something regarded as undesirable)
"The police clamped down on illegal drugs"
crack down (Verb)
To enforce more stringently or more thoroughly.
Crack Down is a run and gun arcade game originally released by Sega in 1989, and ported to the Sega Mega Drive/Genesis in 1990. It was also ported and released to a number of home computer platforms by U.S. Gold. The Mega Drive version of Crack Down was re-released on the Wii Virtual Console in Japan on August 7, 2007 and in PAL regions on September 7, 2007.