You could do this pretty easily. All orbits at the same altitude eventually intersect, and high LEO orbits take decades or more to decay. Moreover, at orbital v

You could do this pretty easily. All orbits at the same altitude eventually intersect, and high LEO orbits take decades or more to decay. Moreover, at orbital velocities, even tiny fragments can destroy a satellite. So if you fill an altitude range with enough orbiting shrapnel, you can ruin the party for everyone. The movie 'Gravity' has some breathtaking visuals of how such a runaway event would look.