Speak Up Already!

I've come to the conclusion that people who do not make a noise or saying anything when a clothing store worker has knocked on their dressing room to see if it's free, causing the door to be opened on an embarrassing, half-dressed situation, are those who turn out to be flashers.

What other logical reason could there be?  They must enjoy getting caught with their pants down literally or something because when I'm changing in a fitting room and I hear the knock on the door and the "Is anybody in here?" I instantly panic and blurt out some noise to stop them from coming in.  On a few rare occasions I'm able to form them into words like "STOP" or "I'm in here!" but usually I'm just so worried about being walked in on that I figure any noise is better than nothing.  And, to this day I have yet to be walked in on at a public dressing room.

I've walked in on plenty of people though, and it's uncomfortable, and would have never happen if people would just answer the warnings.

Side note: 

I almost googled videos for dressing room pranks

but luckily my brain kicked in before I did. 

That could have been bad....