With the number of people taking part and modern technology I think some leaks are inevitable but I don't think it ultimately matters that much. I think the vast majority of the general public will watch and enjoy the ceremonies proper but really aren't bothered by stolen shots or fuzzy film of bits of the ceremony or details of particular costumes or props (I think there were pretty major leaks at Beijing and that went pretty well). A lot of info on the themes has already been officially released. They could hugely increase the security budget (which I'm sure is already hefty) and create roofs and tents for everything but I don't think the massive costs would be justified by any extra benefit - I'd rather the budget was focused on the ceremonies themselves. A cheap deterrent would be to actually carry out their threats, and instead of 'reprimanding' people who are filming or taking photos to actually kick them out - we've been told enough times that filming is forbidden.