An Einstein manifold $(M,g)$ is called scalar curvature rigid if there are no compactly supported volume-preserving deformations of the metric g which increase the scalar curvature. We give characterizations of scalar curvature rigidity for open Einstein manifolds as well as for closed Einstein manifolds. As an application, we construct mass-decreasing perturbations of the Riemannian Schwarzschild metric and the Taub-Bolt metric. This is joint work with Klaus Kröncke