Security was sent up every time I have been locked out of a hotel room. They're always happy to open the door for me, but won't leave until I satisfactorily identify myself (with ID that is usually locked in the room).
Wow, that never happened to me. I always get the card re-keyed without any kind of security. And that is from low 3 stars to 4 stars hilton and Cliff in SF to name a few.