[spatulon]

Two problems that have occurred in recent times when Dota tournaments have not used booths:

- the crowd whistling to tell their favourite team that the enemy team is making some kind of secret play (e.g. taking Roshan, or using a smoke).

- clearly hearing the play-by-play commentary that's being played to the crowd over the arena's loudspeakers, which can also give away information about what the enemy team's doing.