[nailer]

Indeed. The 'they don't know where to go, as they can't get to Google Maps' also doesn't ring true - if the police are arriving, I suggest most people would move away from the police, whether they can get to Google maps or not.

[RiderOfGiraffes]

Odds on the police would use "kettle" tactics, so there would be nowhere to go away from them.

It's not true, it hasn't happened.

Yet.

[semanticist]

I believe the Met. are using that much less now, since the whole fiasco with the G20 protests in 2009.

[nailer]

Its a flash mob, not a protest. The police would likely ask the mob to forest the area, as