The notion that a basket case bureaucracy like the US government could instigate a false flag on its biggest and most prolific city and get away with it, only to be fooled by uneducated neo-hippies and crazed conservatives via the use of the internet and nothing more is both hilarious and pretty sad. Having said that, the whole conspiracy schtick is quite entertaining. These people should become authors with imaginations like this. One conspiracy that isn't entertaining though, is 'GLOBAL WARMING'. Even ignoring that whole 'facts' thing, suggesting that global warming is a lie is to take the assumption that greenpeace has more political and monetary power than Exxon, Shell, PD, Texaco, Aramco and every other fossil fuel company combined which to me suggests either severe damage to the neocortex or a vested interest in global warming being a Hollywood liberal hoax.
In any case, the majority of governments tend to wash their dirty laundry in public nowadays anyway, so why even bother with some complex conspiracy.