This was a terrible idea from the start. In the best case scenario, what is supposed to happen? The sites I visit suddenly start being served as shells of their former selves in order to save the compute cost of rendering them? Web designers are supposed to figure out an entirely new design mode for the whole site to cater to visitors with low batteries?<p>Now back to the real world, where many sites I visit peg my desktop CPU trying to serve so many ads and so much tracking to squeeze every possible cent of profitability from my visit. If there's a war against ad-blockers, did we think these sites would relent and say, oh, OK, I see you might be low on battery, I'll serve just the content you want <i>this time</i>?!<p>No, this is a purely client-side concern, with plenty of purely client-side mitigation which can be put into place. That the protocol actually specified 14m degrees of granularity -- from what at the very least ought to have been a binary setting -- makes me wonder if the point wasn't user tracking all along.<p>Missing from the article: Do all user agents actually provide this information in request headers? Is there a way to shut it off?