[Windflier]

"Perhaps the search was conducted at the wrong frequencies, or those signals were hidden by radio interference from Earth."

I highly doubt that ET broadcasts on the radio band. They're probably using some kind of quantum entanglement transmission technology.

When our people finally discover the same technology, the waves are going to explode with communications from ET.

[justa-hairyape]

Whatever it is, it would have to be way out there for us not to see it or capture the communication. Their technology would probably appear God like to us.