Usurpation in its literal sense means forcibly taking a thing from another. Usurpation is unlawful. Any person knowingly and willfully usurping the property of another is held to be a criminal and a sinner, and therefore, he becomes liable for compensation. Forcible possession is oppression in an extreme form of which there is a strong condemnation both in the Holy Quraan and Hadith.
Sayyiduna Salem (radi Allahu anhu) from his father reported: “Whoso extorts any portion of land unjustly will be sunk down unto seven earths on the Resurrection Day”. (Bukhari)
Sayyiduna Yah’li Bin Murrah (radi Allahu anhu) reported: ‘I heard Rasoolullah (sallal laahu alaihi wasallam) saying, “Whoso encroaches upon a land without title therein will be put to near the burden of its earth on the Congregation Day.“ (Ahmad) Same reported: ‘I heard the Messenger of Allah (sallal laahu alaihi wasallam) saying, “Whoso takes a span of land by oppression, the Glorious and Almighty Allah will give him the trouble of digging it till he reaches the last of the seven earths, and then he will be thrown down till the Resurrection Day till he will be brought for judgment among men.” (Ahmad)