Prime Directive?
The bigger question is, why would the aliens want to contact us, but not want everyone to know they exist? Wouldnt it be very simple for them to set down Central Park and ask for a news conference?
Evidently,
Their satanically driven agenda is better suited to seductive under the table moves as long as possible.
Also, God has some sort of lid on whatever happens from whatever sources. No body gets away with anything without His allowing it.
And God has HIS TIMING which reigns supreme.