What else? (Score 1)

In 19th century, there were projects to contact the Martians by means of huge fires set up in deserts. After invention of radiocommunications, Earthlings are searchings for traces of similar radiocommunications from other civilizations. Now, when the communications are becoming optical, of course, it is "reasonable" to look for traces of optical communications. Of course "they" must be using it just because we are using it. I wonder, what SETI-like projects will try to detect several decades later? And centuries later?