I think what he means isn't that the beam can be damaged, but that the actual beam trail can realistically cause damage, rather than the head being the only dangerous part. It's a good idea on paper. I think I suggested this once, actually. Thinking about it more though, you'd have to make the damage minor. Otherwise, people would be recreating that racing level from Tron, escept in 3D, aiming not to his their opponents, but to trap them in a cage of deadly beams. If 1.3 has implemented the "springy" beams I've heard about however (which tries to maintain a straight relationship between the head and the player using it rather than the artistic beam spam we see in so many entertaining potw's) then this wouldn't be as much of a problem.