as a sparky also, I think it should be a crime punishable only by death....
its a piece of piss once known how do it correctly..
once you have zipped up the tie nice and tight, grab the tail (shitty bit to be cut off) right up at the nut, as close as you can get, but be sure to have your pliers(and only pliers will work correctly, leave the sidies in the tool box) inline with the tail, running parallel with it..with a nice firm grip on the pliers, its just a short sharp twist, either way should work (if you are a south paw!)
works almost all of the time if done correctly...no need to cut with a hobby knife or anything stupid like that, asking for trouble!
have a go, you will be surprised how friggin easy it is!~