Spam-detectors, bot-detector and -banning tools, developers of the former three, powerusers. They all went when reddit shot itself in the head.
Now reddit is bleeding out, flooded by spam and bots, quality decreasing every day. These people will probably not come back, no matter what reddit does now.
Also light is not sentient, i knows when it is being measured and does different things, but its not sentient DO NOT WORRY!!!!!!1!1!!!1!