Security never entered my room, nor did they want to. Why? Because I did the simplest thing. I didn't keep the DND sign on the door so I had normal maid service. I like fresh towels and made beds.
If you leave your DND up, security will come to your room once a day and take a quick visual inspection. Yes, we all know this is mostly 'theater'. If you're there alone and are uncomfortable with people in your room when you're alone, then stand outside the room during the inspection.
Some people aren't happy unless there's drama. I see many people at DEFCON who imagine they're 007 and a host of three letter agencies are interested in them. Good for them! (I suspect Marc Rogers, the DEFCON security person who resigned, simply didn't want to deal with drama anymore when there are real battles to fight.)
For the rest of us, it's a nice convention where we can talk to real engineers and security researchers about problems that affect us.