In this specific instance:<p><i>The idea that astronomers had stumbled on such a structure triggered headlines round the globe – though not for long. Subsequent research has now undermined the idea. “We have found that light of different wavelengths is blocked in different amounts: exactly what you would expect from starlight passing through a dust cloud,” said Lintott.</i>
From wikipedia: It has been suggested that it is an alien megastructure, but evidence tends to discount this suggestion<p>Just read wiki on the topic seems to be the best idea these days, much less pompous and no fabulation unlike the article. It also has distant red dwarf companion, of course no mention of this at all in the article.<p>Not sure why guardian needs to chase sensationalism, I guess view count trumps all other metrics.<p>Also, haven't heard any rational objections for Dark forest theory, any sufficiently advanced civilization to build this would be tremendously stupid to expose themselves to whole Milky way and few surrounding galaxies.