> Eventually probe will find planet with life. May be life is more abundant than we imagine now. May be not. Surely there will be protocols for the probe to investigate life. It's hard to imagine what those protocols would be. May be explore freely until certain technology advances are observed and then hide. So may be our ancestors saw alien probes on a regular basis and just didn't care. But now those probes observe that we've got quick airplanes so they hide better.

Surely the protocol wouldn't be "show a tic tac in the sky and disappear foerver"