They will search bags going from the campsite into the festival site. How thoroughly they do that varies greatly from one security person to the next. If they find any cans they probably won't confiscate them, but more likely they'll offer you the option of drinking them there and then or taking them back to the campsite
Ahoy hoy. Going to this on Friday for the first time, excited for my first proper overseas fest! Anyone who’s been before - what’s the deal with bringing booze from the campsite to the stages? Theoretically they can check but they never do (like Green Man) or actually might take cans off you (like Reading)?