I came across a variant poster:
It turns out that this is a hell of a loophole.
The actual quote is in Quran 5:32. And the very next verse, 5:33, explains a little bit more what the penalty for "mischief" (or "corruption") is:
5:33 Indeed, the penalty for those who wage war against Allah and His Messenger and strive upon earth [to cause] mischief is none but that they be killed or crucified or that their hands and feet be cut off from opposite sides or that they be exiled from the land. That is for them a disgrace in this world; and for them in the Hereafter is a great punishment,Wikipedia explains that this is the crime of Fasad:
Fasad (Arabic: فساد /fasād/) is an Islamic concept which means spreading mischief in a Muslim land, moral corruption against God, and any form of expression or activity by non-Muslims or apostates of Islam that creates disorder in the Muslim community.The definition of Fasad is so expansive that it can be used to justify murder in nearly any circumstance that an Islamic cleric or Islamic government wants.
In recent years, the law has been included in the legal code of the Islamic Republics of Pakistan and Iran. In Iran it has been used to prosecute or threaten political opposition figures.
From the Tafsir of Ibn Kathir, "fasad fi al-ard" is the act of disobedience to God.
In his Tafsir, As-Suddi states that disbelief in Islam, disobeying sharia and acts of disobedience of authority is committing mischief on the earth.
Sunan Abu Dawud, in 38.4359, confirms that the punishment for fasad under Islam applies to Muslim and non-Muslims.The exact same verse that Muslims use to "prove" the morality of Islam happens to also contain the justification for murdering innocent people - in the name of Islam.