Sounds like most of you all subscribe to the 'Paranoya Mean Destroya' tune. All we have is a 12 buck Harbor Freight driveway alarm to tell us when a vehicle is in the drive by the house. and I agree with Mossy, dogs are basically useless as watchmen. Our 'mean' dog would go for a ride as well and probably leave nose prints on the glass. The big deterrent is my NRA sign in the front yard and my ***** sign. If you can read, you know where I stand on stuff.
The dogs that give me the most concern are the little ones I call 'ankle biters' The little ones seem to be the most agressive in my experience. The big 'guard' dogs are really docile. Big bark and no bite.