That seems like it could also mess with mouse selections if the text moved when selected. maybe even causing endless jitter. I kinda wonder if "page scrolled '

That seems like it could also mess with mouse selections if the text moved when selected. maybe even causing endless jitter. I kinda wonder if "page scrolled 'cause X was selected" type data extraction attacks might play a slight role too. Although I suppose if you've managed to inject CSS all bets are off..