I have seen people defeat almost every type of alarm and anti theft device known. Once they simply used a tow truck and hauled my car off with the alarm blaring and no one even bothered to question them as they looked like a legitimate buisness! So I simply dont worry about it when out and about.
At home I have a German Shepard that loves to sit in a dark corner and ambush intruders. I figure if you can get past him you want the bike more than I but the cops will find you when you are getting stiched back together at the hospital!