What do you mean by "420" festival? That name brings to mind a festival celebrating cannabis, calling for legalization... something of that sort. A place where there are so many stoners and so few cops that you could probably light up a joint and no one would bother you.

As far as I can tell this thing is an environmental awareness festival, cannabis users are no more likely to be there then Al Gore, and if anyone lit up a joint the secret service or D.C. police would be on them like flies on George W. Bush...