Yeah, I vaguely remember it making the news in the 90s, and I stopped standing at that point. I had one teacher tell me once it was "required" that I stand. I just said "no thanks" and continued sitting, and he dropped it.
It wasn't a big protest in my case though. I normally had a CD player stuffed in my belt, and standing made it more likely to fall out and get noticed. I generally avoided standing as much as possible in those days.