Judging on behaviour I witnessed in the red camp I'm amazed it was just the one bottle that was thrown...
I attended V at Chelmsford this year and despite being 40, it was my first ever festival. Not knowing anything about the camps, I'd booked us (me and my kids aged 16/13) in red camp which I later found out had a bit of a rep.
When I got there I was told by the stewards that the quite zone was okay for families, so we pitched up there. The Fri/Sat nights were fine - rowdy and raucous behaviour (as I expected) but all quite jovial - shouts of 'Alan', singing, laughing, swearing, etc.
On the Sunday night things changed drastically. Several groups of people felt it acceptable to walk up and down all night at the railings to the quiet zone shouting 'oi, wake up quiet zone w***ers you bunch of c***s', rattling the railings and pelting bottles of pee and full cans of lager at our tents. They set fire to at least three tents and were throwing aerosols onto campfires to create explosions. At one stage a bloke from a tent nearby shouted at them to clear off only for them to tear down the railings so that they could try and get to him.
I'm not naive (and neither are my kids), I've lived in rough areas, been to plenty of football matches (home and away) and gigs, heard every swear word under the sun etc, but behaviour on that night was just threatening and really intimidating for those of us targetted. The onsite security seemed to be fighting a losing battle as there were so many incidents going off that they couldn't keep up.
I loved the festival itself but wouldn't ever want to camp there again, especially not in the red camp where to pitch your tent on the quiet bit you seem to be inviting yourself to be attacked by a bunch of chavs with nothing better to do.
If nothing else it was a lesson to my kids of how not to behave.