https://www.britannica.com/video/Animation-speed-of-light-laser/-221775The point, "Irony," yes, is that shine a laser on the surface
of the moon. There's a point of light.
...the point is this point, of light. Point. The point.
Alright, so now whip this POINT around like the moon was a
giant kitten you were trying to drive crazy and that POINT
will zoom across the surface of the moon FASTER then the
speed of light.
You're on the planet earth, pointing a laser pointer at the
moon (this is the point here) and moving that point from
side to side, up & down. Your hand isn't moving at the speed
of light, much less faster than light, but the point of
light on the moon is.
Call it a "Dot" if that makes you happier...
Signals would be like this, signals from aliens.
But, SETI isn't interested in such signals.
A signal from another world would originate at a point on
the surface of a planet that's spinning, even as it's
circling a sun, even as the entire solar system it belongs
to is moving within a galaxy that's in motion...
Damn. That signal, that point of light or beam of energy
is whipping around much faster than your laser point on the
moon!
SETI doesn't want little bursts. SETI isn't interested in
any signal such as we are likely to detect, because it
would be very brief and unlikely to repeat.
There is an alternative here, and that's an alien world
communicating with a spacecraft. This would require a very
powerful signal, one would presume, because it's potentially
traveling well beyond their world, and it could potentially
lay between us and the aliens who are trying to communicate
with it.
Still, excessively unlikely to be the kind of signal that
SETI is interested in.
The distances are so great that, even at the speed of light,
a signal couldn't be pointed at us, where we are, but where
we'll be when the energy reaches us. So it's pretty much
impossible for SETI to detect any signal that they might pay
attention to.
So SETI could only detect signals in very close proximity
to our planet, like from a probe, or a signal from a
civilization much more advanced than we are, deliberately
trying to each us.
But could they?
Most of our earth is uninhabited by mankind. Like 70% is
ocean then there's deserts, mountains, tundra...
If a signal is concentrated enough, in all probability it's
going to fall on deaf ears, which is to say no ears what so
ever.
No one will be there to hear it.
So a signal has to not only be strong enough to reach us
while remaining coherent but wide enough to be detectable
over a significant area.
We keep getting into a more & more specific, limited type
of signal that SETI would ever bother with... a less and
less likely scenario of detection.
The most likely signals to reach earth:
Extremely weak, indistinguishable from background noise
with present technology, or very brief high powered
bursts.
SETI isn't interested in either. in fact, they'd dismiss
both!
-- https://jtem.tumblr.com/tagged/The%20Book%20of%20JTEM/page/5 
My SETI eats boogers