Cloning or moving a redstone block using the /clone command can activate blocks near the destination that would not otherwise be powered after the clone or move.

In the attached image, cloning the redstone block above A to the position above B activates B (as it should), but ALSO activates C (it should NOT).  This occurs whether or not the block is cloned or moved via the 'move' keyword.  C only seems to be activated if B is a command block (if B is quartz, C does not get activated).