By the search...
I presume you are talking about investigating UFOs and not SETI. It is
very important to separate the two.
While SETI certainly has its limits, those conducting it are doing so within the
bounds of science, current and real technology, and scientifically plausible
ideas.
If we don't do something to actively search for them, I doubt we will ever
find them so long as remain stuck on this planet. The odds of them finding
us at this stage of the game are pretty remote.