Lighning bolt destroy command blocks

After having played a bit around with command blocks, I discovered a small bug.
If you enter the command summon ligningbolt ~ ~ ~, the command block has been destroyed !
Curious, I tried to use the command on at the position of an another block. It got destroyed too.
I think it shouldn't be impossible to check if the block is "empty" (canPassThought property maybe?) to set the fire.