Galactic Weapon?

I am sure many of us have watch Starwars, Gundam series or any sci-fi film that has this almighty weapon shooting through the space. This had very well became a reality, if you have watched the news or read the article on yahoo, you'll probably know, there's this black hole that shoots a stream of deadly radiation particles across the galaxy, clearing anything in its path.

Well, imagine it as an "advance civilization" trying to show their dominions across the galaxy. What if its pointed towards Earth? This can be a great subject for the next Steven Spielberg film...