Is the "okay" hand gesture now unacceptable to use in class? While teaching a class last week, I made the widely-recognized hand gesture (an open circle with the thumb and index finger, with the other 3 fingers loosely or sharphy extended... I'm not sure exactly how mine looks, as it's like muscle memory and I don't consciously think about the exact shape I'm making) while simultaneously saying "okay...". I can't remember the full sentence but it was something related to the math course I'm teaching. 

Now I suddenly learn that it means "white power" to some people (some Americans). To make matters even worse, I'm white, and I make a very similar-looking symbol while indicating 3 things (some use the middle 3 fingers for this; but I've always done it the other way) or counting to a number between 3 and 5 with my fingers.  Good heavens!  

Would I possibly get into administrative trouble for doing this, if a student were to report it?
The whole "White-power" hand sign started as a joke from 4chan or something like that. It was kind of a ploy to get the more gullible liberals all worked up for nothing. It was kind of laughable at first. However, it would seem that it's becoming more and more accepted as an actual WP symbol. I believe that some white-supremacist groups have even ended up adopting it. Still, I wouldn't worry about it as long as it doesn't seem as if you are actually pushing the agenda. 

You could always swap it for "thumbs up" or, my favorite, good ol' finger guns.