In November of 1974 a small group from S.E.T. I. SETI, Search for Extraterrestrial Intelligence used the radio dishes at Arecibo to send out a message to whoever might be listening.
In January 1993 Arecibo received a message back
They heard a voice across the land of freedom
Voice said Earthlings
This is a message from outter space
All your weapons of evil must be destroyed. You have only a short time to learn to live together in peace.
