Aliens could be sucking energy from black holes. That may be how we'll find them.

Perhaps there is a possible way/methodology for obtaining energy from "mini Black Holes" which could possibly be created in particle colliders such as the LHC. Such would involve matter being converted into energy via E=Mc^2. How practicable, how useable, how doable, how dangerous implementing such a process on Earth might be is speculative and worrisome in the same way nuclear energy is currently, only more so. With the nearest Black Hole to Earth being 1000ly distant, it would seem an "impossible dream" to obtain either energy or definitive data about any extraterrestrial aliens in any time fame to benefit life on Earth. (given that our best vehicle technology provides less than 5% the speed of light).
The article said "We have only done the physics in this paper," he said. "But I am now working with a colleague of mine to apply this to reality, to look for civilizations, to try to see what kind of signal you would need to look for."

My observation. Keep looking :) We have more than 700 host stars documented now with multiple exoplanets orbiting them. Our solar system is confirmed to have life on Earth :)