Except that those rules, published in an official book and nowhere else, turned out to be wrong. You're allowed one bag, 25 litres or less, soft-sided, must be able to fit under your seat.
I will stand corrected on that point.Reading the T&Cs
"The following is a non-exhaustive list of restricted items which may not be taken into a Venue (LOCOG reserves the right to amend this list, generally, or in respect of any Venue or Session): food (save for baby food), alcoholic and non-alcoholic beverages (save for baby milk and other valid medical reasons), liquids in containers of greater than 100ml in size, needles (save as required for valid medical reasons), animals (save for assistance or guide dogs), weapons (including knives), illegal drugs, other illegal substances, fireworks, firecrackers, poles, flagpoles, sticks,
large photographic equipment (including tripods), bats, large umbrellas and other blunt instruments, motorcycles, bicycles, roller-skates, skateboards, or other types of skates, electronic transmitting equipment, flags of countries not participating in the Games, large flags or banners, horns, whistles, drums, rattles, musical instruments, lasers or any other devices that in the opinion of LOCOG may disturb a Session, objects bearing trademarks or other kinds of promotional signs or messages (such as hats, T-shirts, bags, etc) which LOCOG believes are for promotional purposes, counterfeit products, balls, rackets, frisbees or similar objects, large quantities of coins, lighters, advertising or promotional material of any kind, printed matter bearing religious, political or offensive content or content contrary to public order and/or morality, bottles or containers made of glass or other material, flasks, thermoses, refrigerators, large objects such as suitcases or bags, and in general any material that LOCOG may deem dangerous or that may cause damage or disruption to a Session."
So it now just says large photographic equipment - I would bet that pretty much any dSLR camera with a lens could be construed as large photographic equipment lol