I have heard of it everytime we go away!!! We don't go away much where we use hotels but over the last 8 years, everytime we have gone we have been required to put money down on a credit card, no cash. Not sure if every hotel is like this, but the ones we chose to stay at in the past have all required you to do it. One was in Moncton and one was in Halifax. I do remember these because they were most recent.
I am not worried about getting the money back, I always do. But an idea if you are worried, take pictures of the room before you leave with your camera. If your camera has date and time all the better!!! If they try to pull that, you have proof you weren't the one who trashed it.
Hope that helps with your worries for the next time you travel and they ask for this.