  Narrowband radio search for extraterrestrial intelligence (SETI) in the 21st
century suffers severely from radio frequency interference (RFI), resulting in
a high number of false positives, and it could be the major reason why we have
not yet received any messages from space. We thereby propose a novel
observation strategy, called MultiBeam Point-source Scanning (MBPS), to
revolutionize the way RFI is identified in narrowband radio SETI and provide a
prominent solution to the current situation. The MBPS strategy is a simple yet
powerful method that sequentially scans over the target star with different
beams of a telescope, hence creating real-time references in the time domain
for cross-verification, thus potentially identifying all long-persistent RFI
with a level of certainty never achieved in any previous attempts. By applying
the MBPS strategy during the observation of TRAPPIST-1 with the FAST telescope,
we successfully identified all 16,645 received signals as RFI using the solid
criteria introduced by the MBPS strategy. Therefore we present the MBPS
strategy as a promising tool that should bring us much closer to the first
discovery of a genuine galactic greeting.
