The Fifth Amendment addresses the protection of several rights of citizens, one of them is Eminent Domain, which it's the process in which the federal and state governments can acquire private property in order to convert it into public use. The amendment states the following:
No person shall be (...) deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
So, if the government were to seize property under Eminent Domain and gives the property for personal use, it is violating the Fifth Amendment because this Amendment states that the government can seize private property ONLY IF it the property is to be taken for public use and, furthermore, the government has to pay the landowner just compensation.