I came upon this gem of a hotel room warning sign.

I have no doubt that messing with a hotel room fire sprinkler could lead to some problems.  But is it really necessary to warn guests not to hang clothes from the sprinkler?  When was the last time you stayed in a hotel and had so many things to hang in the closet that you needed to find additional space?

Maybe the problem is that guests were hanging clothes from the sprinkler, to set it off, to use as a washing machine.  In that case, there should have been a sign on the microwave warning people not to use it as a dryer.