The Messenger of Allah (sal Allahu alaihi wa sallam) said: “O people of the Muhajireen! There are five things which if you ever indulge in, calamities will engulf you. Allah forbid that you ever indulge therein.
One is that when among any people promiscuity (fornication and adultery) become widespread, plague will overtake them as well as new diseases which were previously unknown;
and when any people cheat in weighing and measuring they will face drought, famine, hardship and the wrath of unjust tyrant rulers; and when any people withhold Zakaat, rains from the heavens will be withheld from them and had it not been for the presence and needs of mute animals even a little sprinkle of rain would not fall;
and those people who break their covenant with Allah and His Messenger will fall prey to enemies;
and the people who enforce unjust laws will be involved in civil war and rebellion.” [Targheeb]