Abstract: The present invention discloses a protective device for a mobile device (smart phone or tablet), comprising: a frame comprising a first sidewall, a second sidewall opposite to the first sidewall, a third sidewall and a fourth sidewall opposite to the third sidewall, the sidewalls being terminated with each other and attached to a backboard, thereby enclosing and defining a space for accommodating the mobile device; provided with an engaging feature allowing the front camera of the mobile device to be covered or uncovered, at the will of the owner. With the present invention, the front camera can be covered by snapping or sliding a small cover in place, or uncovered by lifting or sliding said little cover, thus ensuring protection from potential hackers using the front camera of the device for illegal purposes. The camera cover can be manufactured in any feasible shape and color (star-shaped, diamond-shaped, flower-shaped, heart-shaped, half circle-shaped, etc. etc.).