I recently moved to a new house.  I installed a home security system about 3 weeks ago.  3 nights ago I went to bed about 4 am after checking (So I thought!) all the doors.  At about 5 am one of my sons came to my room and said that the Police were here.  I got dressed and went down the hallway to his room where there were two sheriff dep.  They asked me if I had heard my alarm go off.  I had not.  They asked me if I had heard them ring the door bell 6-7 times.  I had not.  Turns out they had gotten called by the alarm compnay and had responded to the house.  They then tried the number on the stickers on the window.  I found out later that they were the wrong number for the alarm company.  They had gotten a new one.  The two dep. came in the open door and did a search of the 1st floor, then the basement and had then gone upstairs, where they came to my son's room.  I have since had another "horn" instsalled outside the mastere bedroom.  The dog proved to be a worthless mutt as well.  She did not even know the men were in the house!
 Lessons learned:  1)  Check doors carefully. 2)Make sure that the alarm is loud enough to wake you from a deep sleep. 3) Make sure the @#$#@! alarm company has the correct # on the window stickers. 4) Make sure the alarm company calls the primary # 1st.  I would have heasrd the phopne ring in the bedroom!  I used this as a learning experience and fixed the problems.  Others may not have the police come in first.  BTW seeing two large men in my house at 5am, that I knew nothing about, shocked the hell out of me.  I also switch from my Glock 17 to my G22 as my nightstand weapon. All of a sudden 9mm just did not seem enough.
Stay safe all!!

A friend in a less desirable neighborhood found out he was paying for a security service for 7 months and the company had no record on him being a customer.
Maybe just the window stickers saved him, who knows?
He was lucky.

Never sign up with an alarm company that solicits you...

I would change alarm company's!!! They should have sent out new info immediately after changing numbers! Also it is a good idea to test your alarm every couple of months to see if it patches through to the alarm company!