Normally I think celebrity stories are a criminal waste of news space, a sort of opium of the masses, but in this case I think there's a kernel of an issue in the Kate Moss alleged-cocaine-use story. I think it's a good story to bring to light the worst aspects of public opinion.
Laws are supposed to be enforced equally. They clearly aren't, rich people being treated leniently or altogether ignored. This especially so of "victimless crime" laws, which are in reality either social responsibility or social containment laws. Personally, I think drug use laws are might have some use as the former but currently are designed as the latter.
So when a wealthy celebrity is caught breaking such a law, you get three responses. An angry response that they should be treated as harshly as everyone else, a weaker and rather lame conservative empathetic response that they should be treated lightly because they're nice people, and an altogether much weaker argument that maybe the law sucks in the first place.
I think in this incident, we see a lot of anger that's probably to do with Moss being wealthy, pretty, and female. It makes for a socially divisive "fall from grace" story, which is probably why the Sun printed it. It's a story to make working class people side with the law, against the "filthy rich" icon. Of course they're just being fed an "filthy rich icon".
As far as I can see, Moss had her career destroyed and may be criminally charged over private pleasure harmless to others. The same thing happens to any less glamorous person caught in similar circumstances, and this is a bad thing, so the correct response would be to simply argue for de-criminalisation, like in every other case.