There was a thread a while back about coming home to find 'your door open'...No discussion of obvious B&E, but more of "you forgot to close your door when you left, now what do you do"?
The majority of respondents insisted that they would call 911...
I received a dressing down by stating flatly that I would 'clear' my own house due to the 20-30 minute rural LEO response time...That is IF anyone came at all for something as insignificant as my door being open...
http://thefiringline.com/forums/showthread.php?t=507388