You can take one look at the picture here that shows how much junk is orbiting the Earth and see that it's really crowded up there. Moreover, we keep putting up new satellites all the time. It's not only working satellites cluttering up the space around Earth, we also have all manner of trash and defunct items floating around up there.
The Russian space corporation Energia has announced plans to build a special space pod that will go up and grab about 600 defunct satellites and knock them out of orbit somehow. The satellites will either splash down in the ocean or burn up in the atmosphere on reentry.
The company plans to heave the design and testing complete by 2020 and the thing will have a nuclear power core. The lifespan of the satellite killer will be around 15 years. I wonder how the international community feels about this thing considering it would just as easily be used to knock working satellites out of orbit.