Martha,
Great Pyranees are wonderful, gentle giants. I read about them online just the other night and I'm not too sure they are used for any type of "security work". Bailey is our neighbors, but is at our house more than theirs. She likes to play, sleep is always in her vocabulary and really hasn't responded to anyone coming to the door...guess she wants to see who it is first, then decide to bark or wag her tail.
She is a 125lb lap dog! They are verrrry stubborn and need obeidence training to establish the pecking order of the house....they can take over if you let them. She used to be left alone for way too many hours in a day, so I just kinda took over. Took her to the dog park today and she really wanted to play but didn't know how. She plays with my dog, Tank, but he is about her size. There is a large rescue for them online, I think they outgrow peoples houses and people want to get rid of them....that or they won't put up with the stubborness!!
If you have any in your area, go talk with the owners.....the puppies are adorable!
AndiJean