The PPP-MQM coalition only lasts as long as the killings stay within a certain limit. When that threshold is crossed, the MQM goes out of the government but then quietly returns with a bit of rest and acceptance of some more terms from the PPP. The PPP offers concessions with no intention of sticking to them, so while all this buys time for the government to stay a little longer in power, the actual development of criminals and gangs is gaining strength through unchecked criminality at the street level. The various political and religious groups in Karachi continue sheltering their hoodlums. It is a win-win situation for goons, as no one gets arrested. Even if some really incorrigible ones with the blood of scores on their hands get caught by the police, they get out promptly on bail because of poor paperwork by the prosecution and the implicit threat to the judges.