All my point was...was to tell someone who knows nothing about training or maintaining a protection dog...to get one...and do xxxxxxxxxxx....is a bad idea. If he followed those instructions lets say....and dude leaves his dog home to protect his grow...lets say the roomies invite a friend over...and the friend stumbles upon a room accidentally and the dog bites...thats not a good thing. To each their own. But a bad idea is a bad idea. Would you tell a guy who likes to smoke bud to go and grow some? Dont you think a good understanding of what they're getting themselves into is in order?
But I digress...if they think thats a good idea...then have at it. In the long run its up to him.
Now...Back to our regularly scheduled program lol. Just bringing another aspect to the convo thats all.. Hmmmm...Where did I put my lighter? Again, no disrespect intended.
Unless you remove the voice box dogs will bark/growl a warning if they think you haven't seen them. I've never known them not to, and I'm coming from both angles here protector and perpetrator.
So unless your friend is deaf, and also blind (to not read the sign) everything should be fine.
Dogs are the best criminal deterrant you can get. They even beat guns as I know criminals will target homes just because they know the owner has a cabinet-full. Dogs take a different approach.
The only way to get past a guard dog is to fire a crossbow bolt through the letterbox (if you have one, I'm aware in the us you have outside mailboxes?). Even a well-trained guard dog will run to the letterbox to see who's opening it, this lines the dog up for a perfect shot.
So unless some heartless motherfuckers want to rob you, which chances are they'd rather pick on someone easier, your best bet, better than any alarm system is a dog trained to attack intruders (which is fairly easy when you consider this is their natural instinct anyway, since cave-man days in fact).
Ok, my training methods may not be up to approved spec.'s... but my system works, and i have a loving family pet.