First off everyone seems to think that all beams are just pure light, I will give you that photon torpedoes do sound like that, but there is room for more to it than that. Secondly light does bend by gravitational influence, some astrological objects have been found because a strong gravitational force has caused pinpoints of light to become two points, or something similar. And there is always the black hole that even light cannot escape. With something like the transporter on Star Trek why not simply beam away a portion of another ship out in space? It could be pretty catastrophic with the right part missing.