Laser beam eavesdropping...
Here is a subject that pops up every few years, grabs the press and public by the nostrils, hitches them to the paranoia pony and drags them around kicking and screaming with fear and delight.
We built an LBE to put client fears into perspective when the subject urped up in the 80's. You can read all about it here.
Another experimenter has published an admirable update here.
Movie versions about LBEs may be seen here and here.
Bottom line...
Technically, a lot of fun and very impressive ...in-the-lab.
Realistically, this is not an eavesdropping threat for most people. Relax.