What if you put a powerful laser somewhere on the Earth's equator
pointing up?  Wouldn't it have the effect of sweeping the Galactic
Plane that the article mentioned?

Yes, once it got through the atmosphere. Better to put it in geosync
orbit, with a large solar array or several for power.

Good idea. I was thinking about this and came up with the idea of
putting it on the back side of the Moon pointing directly away from
Earth.  But your idea is better.  You would need lots of power.

This could even be done by a private foundation.  After all putting
something into geosync orbit is not such a big thing, is it?