An interesting twist to this story is that those very same social media are now being used to identify the perpetrators with amazing speed. Names and pictures as well as movies have been made available to the authorities and 10's of people have already been arrested and/or have given themselves up at police stations.

Even worse than the live stream was the radio DJ who was encouraging people to go to the 'party' (he has since apologized).

This relates a bit to the problem of copycat crimes and the reporting of suicides causing an increase in suicides. Publicity increases the problem, but it's hard to get all the media to agree voluntarily on not giving it too much attention.

I wonder how this problem should be solved. In an ideal world you could have a system as in science with independent peer review, to do fact checking and preventing hypes. But of course such a system would be much too slow and you would have lots of people complaining it's not free press.

It can work in reverse aswell. If car fatalities are reported more, people might become aware that cars are dangerous, and drive safer, hence reducing fatalities & injuries.

But considering that party flashmobs like these appear to be happening regularly and often cause considerable damage and bad PR, shouldn't Facebook think about changing the way party invitations work? For instance by asking if the user REALLY wants to make the invitation public?

I don't know whether your idea really helps much, because other times people intentionally make flash mobs, and they can be problematic. It seems to be difficult to address without totalitarian measures.

Doesn't Facebook make it possible to change the status or remove it, once she realized her mistake?

The entire vibe of the event was not peaceful, it was clear from the beginning that people wanted to start shit. After all was over the entire city's central place was littered with glas shards and trash.

2 months prior to the event thousands of people danced peacefully through another city, Bern, also during an illegal party, and there were no riots.

Methinks you have too much faith in mobs; as expected, they smashed and looted. I suppose that was the police's fault?

The problem is a person making a private party invitation public, while being naive about exponential growth as the invite is passed from friend to casual acquaintance to complete stranger to anarchist to criminal.

Two years ago similar problems where arising in France, called Apéro géant. The crowds intended to organize the biggest party at the Eiffel Tower, everyone feared problems. Authorities sealed the surroundings, but let everyone pass through as long as they handed in their alcohol. Once arrived at the location there was not much of a party so nothing happened.

It's going to be interesting to see what happens to social media monitoring, also interested to see what happens with the damages and the people on tape (youtube, fb et all)

Also, a proportional "party" in Paris would be two million people. Have fun controlling that.

Even if some rioting would've started, there would be no houses or shops to demolish, and it would be far easier to isolate the rioting core group from other people.

The mayor refuted such plans with claims that that made the authorities responsible on the occasion something happened. As if that is worse than the current outcome.

In hindsight they should've blocked all access ways to the village (train and roads). I say in hindsight because people simply didn't expect this to go so wrong.

The lesson to me is that mobs are a scary thing. They can turn angry very suddenly as people start to copy the behavior of the first person to throw a stone.

It seems that the authorities where too ambivalent. On the one hand they said please don't come there's no party, on the other hand they prepared a football field for people to go to (without music though). They should've stuck with the former and enforced it by not letting the trains stop in the village and putting up road blocks.

Hindsight says that they should have made it hard to take the train there.

I sort of think the problem will mostly go away on its own, most people aren't going to want to repeatedly act as human shields for hooligans.

Sounds kinda pointless because people can use the GPS on their phones & maps to get to the correct place, signs or no signs.

One disadvantage to that is that the pitch could be ruined then. Thousands (or hundreds) of people on a grass field and it'll be mud city. What happens afterwards when that pitch is supposed to be used? Who pays (potentially) for reseeding it?

It ended with glass bottles being thrown around and riot police answering with tear gas.

It was mostly white trash that look for any occasion to wreak havoc. Fortunately, the place was also packed with local and national media, so lots of the people who trashed the place are captured on video. One can only hope that they'll send them the cleaning and repair bills.

Also, this will increase the interest in automatically monitoring of social media to identify threats.

Having t-shirts printed is a new touch.

But I'm more interested in this:

> A new Facebook page has since been created called "Project Clean-X Haren" to clear up after Friday night's disturbances. It had more than 17,000 "likes" as of Saturday morning.

I'd be fascinated to see a guerilla clean-up crew cleaning the trash, removing graffiti, fixing damage, doing a bit of gardening.

I'm sure like most Facebook initiatives, people "Like" the idea, but probably won't be taking any real action on their own. That's for other people.

This photo [1] is from during the riots but helped to restore my faith in people too.

[1] http://www.flickr.com/photos/pixel-eight/6024429000/

Seems like very much on topic for HN given that quite a few of us make a living and/or are creating new social media sites.

I see this as a similar to an engineer seeing a mainstream news report of an unintended side effect of large scale engineering project.