I somewhat agree with MrUmp1. If the person sliding hits the catcher to knock the ball loose I think that's smart baserunning, but if the baserunner does maliciously try to knock the ball loose of the catcher by plowing through them, I do believe the player should be immediatly ejected and the run should not count. This reminds me about what happened in a softball game between BC and HF. The BC girl plowed the HF catcher down and was ejected, but the run still counted. I don't even think that the run should have counted!!