Right.
When PhotoPass contacted us to see if we'd let them use our photos on marketing materials, we had to sign a waiver and send it back to them. (We haven't seen our likenesses anywhere, but we did get two vouchers for free PhotoPass CDs).
A signed waiver is not the same as a disclaimer.
If they add a disclaimer to your ticket media that says something like, "If you're here, we can take your picture and use it however we want" they can probably get away with it. Similar to any sporting venue where you might be on national television.
And I believe they do have a such a disclaimer. There's also a disclaimer on all theme park tickets asserting that you release the company from liability from injury upon use of the ticket. And we all know that doesn't shield them from anything. These disclaimers aren't absolutes.