Chavs are basically working class kids (and adults) who wear the same clothes, of a general low intellect and only like mainstream music, movies and opinions. When i was growing up you had punks, goths, new romantics, rockers, indie kids and then the trendies. These days a lot of kids dont seem to want to have an identity so they just follow the crowd.
The justice system in Britain seems to getting more lax and consequently youths are more brave in what they can get away with. So a lot of teenagers have no respect for anything at all these days.
This site is so funny:
ChavScum - Welcome