on the rules and regs of t4otb it says that bringing food/drink especially alcohol is prohibited as there are plenty of food and drink stands on site. You are only allowed to bring 1 bottle of 500ml water unopened. I guess thats so they know its defo water in the bottle. They say they search everyone but i doubt it since they'l have like 40000 people to get in, so its up to you if you wanna risk it!
also its on professional recording equipment that isnt allowed digital cameras/disposable cameras/mobiles are fine!