as said before.. some persons DO need guard dogs as such (trained)...

every dog WILL guard his/her home by nature... but it will differ from a dog trained specifically for that matter....

IMO tehre is some point that a naturally guarding dog will break (start wagging at intruder or run away) but a trained guard dog will stay put until told otherwise... hence why police dogs are trained to GUARD and protect...

it may also be the case that a naturally guarding dog, bares teeth, luges and bites but wonīt let go... and a traind one will do that on command...

as said also the definition of vicious might be missinterpreted by different perceptions.... a non-stop barking dog lunging at the fence might look vicious to the people on the other side but to the owner it might be just his dog guarding his territory...

in my case... with huskies.. when at play to many many countless people they are vicisous dogs... those who know how they play itīs nothing like it, just playful dogs....

I donīt condemn people having guard dogs, as long as they are well cared for and loved... thatīs another reason for the different breeds out there.