Factory Theft detterent system, how effective is it?

[MJB_Hummer]

Could someone expand on how it is so easy to break into the vehicle? I did not get some of the earlier posts about popping the handle, etc.
I just had my 03 H2 broken into. They got my wife's purse and it was like they had the key or keyless entry remote. The H2 was locked like I left it but the stuff inside was gone. I had seen something on the news about some late model GM codes and frequencies being compromised also. I can't believe they got in and out so easy.