Sorry I'm going to be against the OP on this one.
#1 - if you TRULY had an issue with all those people in the hall on the way to your room, then turn around go back to the desk and ask for a different room, that they clear the hall whatever then you would have had no issue with people knowing that the female was in X room (there is a bit of
that goes here, but there is some leeway with the sentiment)
#2 - You don't say what time you checked in and that is very important because calling security to remove people from the hallway during regular hours (pretty much between 9 and 9, and maybe later) without seeing if they'd disperse on their own, etc. is petty IMO. If they weren't overly loud, what was the issue? If they were loud, then perhaps some comments when you walked by would've been enough. I have called security as recently as last week, but that was after being woken up at 2:30 am and then kept awake for close to an hour before I called down for the party across the hall behind the closed door.
#3 - Being female in a hotel full of males ... could be fun is my first thought, the second is what's the big deal? How do you know any hotel you stay at isn't filled with men and no other women at any time? Really - in my work women are almost always in the minority, that's life ... unless someone said something to you or comments were made about you or the conversation you overheard was particularly offensive to make you directly uncomfortable, I think this is a total non-issue. Now if any of those were the case, then the situation is totally different AND why'd you remain in the room/at the hotel, etc if you were
truly uncomfortable.
The fact you continued to your room and didn't turn around, you chose to call down to have the people removed from the hall without making any comment yourself friendly and/or in passing and are concerned just because there were a lot of men in the hotel when you were there .... I don't see a problem with the hotel or the conference attendees. Sorry to disagree.