do not annoy me

"Whoever...utilizes any device or software that can be used to originate telecommunications or other types of communications that are transmitted, in whole or in part, by the Internet... without disclosing his identity and with intent to annoy, abuse, threaten, or harass any person...who receives the communications...shall be fined under title 18 or imprisoned not more than two years, or both."

"But why should merely annoying someone be illegal?"