No trespassing signs can be useful to property owners—especially on large tracts of land or land that is not developed—to put persons entering the property on notice that the property is private property and if they do not have permission to enter, they may be committing civil and criminal offenses related to trespassing. In some states notice is required for a trespasser to have civil or criminal liability for entering the property without permission.

No trespassing signs may also protect a landowner against liability to a trespasser, as a lower duty of care is owed to trespassers in some states, and putting a person entering the property on notice that they are trespassing may strengthen the property owner’s defense against any liability claims if the trespasser is injured on the property.

In West Virginia, property owners can use 'no trespassing' signs to deter unauthorized entry and reduce the risk of liability. According to West Virginia Code §61-3B-3, trespassing on property without permission is a misdemeanor offense, and the presence of 'no trespassing' signs can serve as a clear notice that entry is prohibited. This helps establish that any person entering the property without permission is doing so unlawfully. Furthermore, under West Virginia's premises liability laws, landowners owe a lower duty of care to trespassers than to invitees or licensees. By posting 'no trespassing' signs, landowners may strengthen their defense against liability claims should a trespasser get injured on their property, as the signs indicate that the trespasser did not have permission to be there and was therefore assuming the risk of injury.