Presumably this is so sale can be stopped in the event of trouble, as on an aircraft.

Neil

No, it's so people will purchase the substantially more expensive options available inside the venue.

AFAIK the food and drink is priced the same in the venues and in the common domain of the park.

Knowing a few event management people, I can safely say it is for both reasons. They and the police are concerned about dealing with over-served patrons. However they are even more concerned about making a big profit for their bosses and bonuses.

I know one stadium that has about 15 thousand seats that would earn a few hundred thousand on an average night in F&B sales. So for the Games, add up all the nights and all the stadiums and all the tickets sold and it should be nice windfall if managed correctly.

The prices are not that different from any other licensed establishment in central London, and in most cases any other entertainment venues wouldn't let you take your own alcohol in either.

I was struck on Opening Ceremony night that by the time of the athletes parade, there were very long bar queues and patrons were being limited to "4 alcoholic drinks per order", although it's possible that this may have been due to diminishing supplies rather than public order concerns. Bar staff had however not been properly briefed as they were comfortable selling 4x 70cl bottles of wine to one customer...

"4 drinks per order" rules are often in the interest of them not being dropped!