In this paper, we prove that every *-representation for a discrete twisted C*-dynamical system (G,A,α,ω) (on a C*-algebra) is automatically contractive with respect to the L¹-norm on C_c(G,A).

The author thanks Judith Packer and Dana Williams for their extremely helpful comments on this topic. The deepest appreciation, however, goes to the anonymous referee, who offered valuable suggestions on how to improve the exposition in this paper.