Honestly, it ain't really even the same thing. The Occutards have their heads so tightly wrapped in pseudo-intellectual, postmodern theory and shoved so high up their Trustafarian rears, that in this Bizarro-world social construct they've concocted for themselves, they more or less actually believe they're protesting for some kind of social justice.
The NAMBLA goons, on the other hand, just want unrestricted access to young boys for sex. It's not nearly as sophisticated a rationale.