I don't think you can suck an electromagnetic wave without bending space-time like a black hole does. These devices will simply be radio opaque. If you place a

I don't think you can suck an electromagnetic wave without bending space-time like a black hole does. These devices will simply be radio opaque. If you place a perfectly black object on the floor of a room that has a glowing bulb on the ceiling, the room will get relatively teeny bit darker as the carpet won't be reflecting as much light as it was reflecting before but this black object can't suck in light that is not coming its way. So, no matter how many such black objects you place on the floor, the room won't become dark. Unless you are talking about a Great Wall of China of these Nokia phones that is tall enough to cross ionosphere...