This means that a message could be sent to an individual, rather than everyone who crosses the beam of light. It also opens the possibility of targeting a message to multiple individuals.
(Ist zwar keine VT. Passt aber imho zu den Aluhut Themen.)
New Technology Uses Lasers to Transmit Audible Messages to Specific People | News Releases | The Optical Society
Researchers from the Massachusetts Institute of Technology’s Lincoln Laboratory report using two different laser-based methods to transmit various tones, music and recorded speech at a conversational volume.