Leave Earthmen or Die!

Murph, Forsyth, and Jamison heard the alien voice warn them. And to each it sounded familiar—a sweetheart, a son, a hated enemy!
In a dwindling spiral they circled the planet, and Murph's cold blue eyes studied the radarscreen. Things looked good: no sign of cities, social denizens or humanoids. He was scribbling notes on his desk when the all-wave above him started crackling.
He watched the green line sweep back and forth along the dial, finally centering on the wave length which was broadcasting. As it focused, the speaker sputtered in.
"... in accordance with Interstellar Code," it sounded like a recording, "... we repeat. Landings and colonizing efforts have been previously attempted upon this planet. They are not welcome and have not been successful. Change course and seek other areas. This warning is being broadcast upon wavelengths available to you and in language translatable by you in accordance with Interstellar Code...." Murphy switched it off and looked at his crew of two.
"Well?" Forsyth grinned at him. "The hell with them! We've heard that from every race in the solar system—one way or another. I say we land."
Jamison shrugged. "Put 'er down anywhere. Makes no difference to me." His scarred lips tightened.
"Okay," Murph switched the set back on. The same record was playing, monotonously.
"Load up with combat equipment, boys. We're going in."
The deadly silver needle tightened the spiral course around the planet, and above Murph the speaker crackled again and went dead.
"Guess they got tired of playing that record," he muttered.
Another crackling and the mechanism blared again.
"... we see you intend disregarding our warning. In accordance with Interstellar Code, it is only fair to warn you...." It clicked off abruptly as Murph jabbed at the switch. No use listening to this outworld nonsense—he'd heard it all before and lived through it.