There's no proof that it has anything to do with Wikileaks, but in a world of IoT devices with no thought toward security, anyone who cares to do so can mount DDOS with the power of a national entity.
What's the point of doing what Assange and Wikileaks have been doing without any moral position? He isn't helping his own case.
No, of course it is not legal to set a trap to intentionally hurt someone, even if you expect that the trap could only be activated by the person committing property theft or vandalism. Otherwise, you'd see shotguns built into burglar alarms.
Fire alarm stations sometimes shoot a blue dye which is difficult to remove or one which only shows under UV. Never stand in front of one when pulling the lever! But they are not supposed to hurt you.
And of course these booby traps generally are not as reliable as the so-called "inventor" thinks and tend to hurt the innocent.
In every non-trivial program there is at least one bug.