A terrifying and apocalyptic scenario could be that NSA ( or some other "big brother" ) created Bitcoin to set up a new global currency in order to associate every address to every person in the world, just to easily control every single transaction of every single user in the world ( 'cause we all know Bitcoin transaction are public ).
In my opinion everything is possible, but this scenario is highly unrealistic. This for 3 main reasons:
1. Bitcoin is open source.
2. Thanks to the aspect above, many developers are able to create new coins, based on Bitcoin algo. Yes, in some cases they made some changes, but the important thing is that they based their coins on BTC. In other words, if Bitcoin never existed, altcoins never existed too, no doubt 'bout it.
A relevant aspect is that Satoshi Nakamoto is still an anonymous, while several altcoins devs are well-know in the community ( like Evan Duffield for example ). So if we have some doubt on Bitcoin cause we don't know who found it, we could simply move to another cryptocoin, which ensure us more privacy are more reliance.
3. If Bitcoin had been created by a so powerful organization ( like NSA ) , at this point, after 6 years, it would be much more popular and adopted all over the world. They would set up a majestic media campaign or even force people to use Bitcoin. Nothing of it happens so I think your theory is quite improbable.
I think point 1 is enough to discredit the Bitcoin is NSA conspiracy theory. They would never do this under open source software, it's self defeating. Im sure they want to get rid of physical cash in the future, and they will release their own "coin" but of course closed source and ingrained within the electronic fiat scam. Hopefully people doesn't fall for it and adopts Bitcoin instead.
