Rule of thumb, all aggressive unwanted information.
Clear? For sure not, like you said. But I am considering (rather dreaming) moving to La Palma, a vulcano island that banned all light advertisement (they did so, because of the observatories on top, but they are cool).
Still, a city without aggressive lights would be nice. Some lights are probably unavaidable in big cities, but light that is purposeful distracting, should be just banned.
And online is kind of a different beast, as we voluntarily go to the sites offering us information (but thank god and gorhill for adblockers)