Many landowners are surprised to learn that under certain circumstances, a trespasser can come onto land, occupy it and gain legal ownership of it. The trespasser may acquire a few feet of property or whole acres in this way. If someone is using your property, even a small strip on the edge, you should be alert to the risk. The legal doctrine that allows trespassers to become owners is called "adverse possession" Although the name sounds nasty (and the results can be), the trespasser is not necessarily an intentionally nasty person. The trespasser may simply have made a mistake by relying on a faulty property description in a deed. Sometimes in rural areas, the person who moves in and occupies several acres may believe he owned it, having purchased it from a Seller who shared incorrect information. Questions on ownership sometimes wind up in court after an absent owner of rural property discovers that someone is living on his land, or when a piece of urban property is sold, and a title company will refuse to issue insurance because the neighbor's garage is found to be standing squarely on the property. If people involved can't work something out (like perhaps a line by agreement), the property owner may sue the trespasser or the trespasser may bring a lawsuit and request the court to settle who owns what.