Due to the ability to transmit signals wirelessly, UK prisons have banned the Nintendo DS (along with some other video game systems). The reason? They fear that the devices can be used to plan a terrorist attack. Of course, should they actually research the system, they'd know that the wireless capabilities of the DS are severely limited.We can imagine terrorist attacks being planned in Pictochat, but we're sure the prison guards would notice someone lurking outside the prison walls with a DS.
